diff --git a/packages/mini/krill-parser.js b/packages/mini/krill-parser.js
index f93c26c5..cdfd4ae4 100644
--- a/packages/mini/krill-parser.js
+++ b/packages/mini/krill-parser.js
@@ -176,37 +176,39 @@ function peg$parse(input, options) {
   var peg$c2 = "+";
   var peg$c3 = "0";
   var peg$c4 = ",";
-  var peg$c5 = "\"";
-  var peg$c6 = "'";
-  var peg$c7 = "#";
-  var peg$c8 = "^";
-  var peg$c9 = "_";
-  var peg$c10 = ":";
-  var peg$c11 = "[";
-  var peg$c12 = "]";
-  var peg$c13 = "<";
-  var peg$c14 = ">";
-  var peg$c15 = "@";
-  var peg$c16 = "!";
-  var peg$c17 = "(";
-  var peg$c18 = ")";
-  var peg$c19 = "/";
-  var peg$c20 = "*";
-  var peg$c21 = "%";
-  var peg$c22 = "struct";
-  var peg$c23 = "target";
-  var peg$c24 = "euclid";
-  var peg$c25 = "slow";
-  var peg$c26 = "rotL";
-  var peg$c27 = "rotR";
-  var peg$c28 = "fast";
-  var peg$c29 = "scale";
-  var peg$c30 = "//";
-  var peg$c31 = "cat";
-  var peg$c32 = "$";
-  var peg$c33 = "setcps";
-  var peg$c34 = "setbpm";
-  var peg$c35 = "hush";
+  var peg$c5 = "|";
+  var peg$c6 = "\"";
+  var peg$c7 = "'";
+  var peg$c8 = "#";
+  var peg$c9 = "^";
+  var peg$c10 = "_";
+  var peg$c11 = ":";
+  var peg$c12 = "[";
+  var peg$c13 = "]";
+  var peg$c14 = "<";
+  var peg$c15 = ">";
+  var peg$c16 = "@";
+  var peg$c17 = "!";
+  var peg$c18 = "(";
+  var peg$c19 = ")";
+  var peg$c20 = "/";
+  var peg$c21 = "*";
+  var peg$c22 = "%";
+  var peg$c23 = "?";
+  var peg$c24 = "struct";
+  var peg$c25 = "target";
+  var peg$c26 = "euclid";
+  var peg$c27 = "slow";
+  var peg$c28 = "rotL";
+  var peg$c29 = "rotR";
+  var peg$c30 = "fast";
+  var peg$c31 = "scale";
+  var peg$c32 = "//";
+  var peg$c33 = "cat";
+  var peg$c34 = "$";
+  var peg$c35 = "setcps";
+  var peg$c36 = "setbpm";
+  var peg$c37 = "hush";
 
   var peg$r0 = /^[1-9]/;
   var peg$r1 = /^[eE]/;
@@ -226,39 +228,41 @@ function peg$parse(input, options) {
   var peg$e8 = peg$otherExpectation("whitespace");
   var peg$e9 = peg$classExpectation([" ", "\n", "\r", "\t"], false, false);
   var peg$e10 = peg$literalExpectation(",", false);
-  var peg$e11 = peg$literalExpectation("\"", false);
-  var peg$e12 = peg$literalExpectation("'", false);
-  var peg$e13 = peg$classExpectation([["0", "9"], ["a", "z"], ["A", "Z"], "~"], false, false);
-  var peg$e14 = peg$literalExpectation("#", false);
-  var peg$e15 = peg$literalExpectation("^", false);
-  var peg$e16 = peg$literalExpectation("_", false);
-  var peg$e17 = peg$literalExpectation(":", false);
-  var peg$e18 = peg$literalExpectation("[", false);
-  var peg$e19 = peg$literalExpectation("]", false);
-  var peg$e20 = peg$literalExpectation("<", false);
-  var peg$e21 = peg$literalExpectation(">", false);
-  var peg$e22 = peg$literalExpectation("@", false);
-  var peg$e23 = peg$literalExpectation("!", false);
-  var peg$e24 = peg$literalExpectation("(", false);
-  var peg$e25 = peg$literalExpectation(")", false);
-  var peg$e26 = peg$literalExpectation("/", false);
-  var peg$e27 = peg$literalExpectation("*", false);
-  var peg$e28 = peg$literalExpectation("%", false);
-  var peg$e29 = peg$literalExpectation("struct", false);
-  var peg$e30 = peg$literalExpectation("target", false);
-  var peg$e31 = peg$literalExpectation("euclid", false);
-  var peg$e32 = peg$literalExpectation("slow", false);
-  var peg$e33 = peg$literalExpectation("rotL", false);
-  var peg$e34 = peg$literalExpectation("rotR", false);
-  var peg$e35 = peg$literalExpectation("fast", false);
-  var peg$e36 = peg$literalExpectation("scale", false);
-  var peg$e37 = peg$literalExpectation("//", false);
-  var peg$e38 = peg$classExpectation(["\n"], true, false);
-  var peg$e39 = peg$literalExpectation("cat", false);
-  var peg$e40 = peg$literalExpectation("$", false);
-  var peg$e41 = peg$literalExpectation("setcps", false);
-  var peg$e42 = peg$literalExpectation("setbpm", false);
-  var peg$e43 = peg$literalExpectation("hush", false);
+  var peg$e11 = peg$literalExpectation("|", false);
+  var peg$e12 = peg$literalExpectation("\"", false);
+  var peg$e13 = peg$literalExpectation("'", false);
+  var peg$e14 = peg$classExpectation([["0", "9"], ["a", "z"], ["A", "Z"], "~"], false, false);
+  var peg$e15 = peg$literalExpectation("#", false);
+  var peg$e16 = peg$literalExpectation("^", false);
+  var peg$e17 = peg$literalExpectation("_", false);
+  var peg$e18 = peg$literalExpectation(":", false);
+  var peg$e19 = peg$literalExpectation("[", false);
+  var peg$e20 = peg$literalExpectation("]", false);
+  var peg$e21 = peg$literalExpectation("<", false);
+  var peg$e22 = peg$literalExpectation(">", false);
+  var peg$e23 = peg$literalExpectation("@", false);
+  var peg$e24 = peg$literalExpectation("!", false);
+  var peg$e25 = peg$literalExpectation("(", false);
+  var peg$e26 = peg$literalExpectation(")", false);
+  var peg$e27 = peg$literalExpectation("/", false);
+  var peg$e28 = peg$literalExpectation("*", false);
+  var peg$e29 = peg$literalExpectation("%", false);
+  var peg$e30 = peg$literalExpectation("?", false);
+  var peg$e31 = peg$literalExpectation("struct", false);
+  var peg$e32 = peg$literalExpectation("target", false);
+  var peg$e33 = peg$literalExpectation("euclid", false);
+  var peg$e34 = peg$literalExpectation("slow", false);
+  var peg$e35 = peg$literalExpectation("rotL", false);
+  var peg$e36 = peg$literalExpectation("rotR", false);
+  var peg$e37 = peg$literalExpectation("fast", false);
+  var peg$e38 = peg$literalExpectation("scale", false);
+  var peg$e39 = peg$literalExpectation("//", false);
+  var peg$e40 = peg$classExpectation(["\n"], true, false);
+  var peg$e41 = peg$literalExpectation("cat", false);
+  var peg$e42 = peg$literalExpectation("$", false);
+  var peg$e43 = peg$literalExpectation("setcps", false);
+  var peg$e44 = peg$literalExpectation("setbpm", false);
+  var peg$e45 = peg$literalExpectation("hush", false);
 
   var peg$f0 = function() { return parseFloat(text()); };
   var peg$f1 = function(chars) { return chars.join("") };
@@ -270,28 +274,30 @@ function peg$parse(input, options) {
   var peg$f7 = function(a) { return { operator : { type_: "stretch", arguments_ :{ amount:a } } } };
   var peg$f8 = function(a) { return { operator : { type_: "stretch", arguments_ :{ amount:"1/"+a } } } };
   var peg$f9 = function(a) { return { operator : { type_: "fixed-step", arguments_ :{ amount:a } } } };
-  var peg$f10 = function(s, o) { return new ElementStub(s, o);};
-  var peg$f11 = function(s) { return new PatternStub(s,"h"); };
-  var peg$f12 = function(c, v) { return v};
-  var peg$f13 = function(c, cs) { if (cs.length == 0 && c instanceof Object) { return c;} else { cs.unshift(c); return new PatternStub(cs,"v");}  };
-  var peg$f14 = function(s) { return s; };
-  var peg$f15 = function(s) { return { name: "struct", args: { sequence:s }}};
-  var peg$f16 = function(s) { return { name: "target", args : { name:s}}};
-  var peg$f17 = function(p, s, r) { return { name: "bjorklund", args :{ pulse: parseInt(p), step:parseInt(s) }}};
-  var peg$f18 = function(a) { return { name: "stretch", args :{ amount: a}}};
-  var peg$f19 = function(a) { return { name: "shift", args :{ amount: "-"+a}}};
-  var peg$f20 = function(a) { return { name: "shift", args :{ amount: a}}};
-  var peg$f21 = function(a) { return { name: "stretch", args :{ amount: "1/"+a}}};
-  var peg$f22 = function(s) { return { name: "scale", args :{ scale: s.join("")}}};
-  var peg$f23 = function(s, v) { return v};
-  var peg$f24 = function(s, ss) { ss.unshift(s); return new PatternStub(ss,"t"); };
-  var peg$f25 = function(sg) {return sg};
-  var peg$f26 = function(o, soc) { return new OperatorStub(o.name,o.args,soc)};
-  var peg$f27 = function(sc) { return sc };
-  var peg$f28 = function(c) { return c };
-  var peg$f29 = function(v) { return new CommandStub("setcps", { value: v})};
-  var peg$f30 = function(v) { return new CommandStub("setcps", { value: (v/120/2)})};
-  var peg$f31 = function() { return new CommandStub("hush")};
+  var peg$f10 = function(a) { return { operator : { type_: "degradeBy", arguments_ :{ amount:(a? a : 0.5) } } } };
+  var peg$f11 = function(s, o) { return new ElementStub(s, o);};
+  var peg$f12 = function(s) { return new PatternStub(s,"h"); };
+  var peg$f13 = function(tail) { return { alignment: 'v', list: tail }; };
+  var peg$f14 = function(tail) { return { alignment: 'r', list: tail }; };
+  var peg$f15 = function(head, tail) { if (tail && tail.list.length > 0) { return new PatternStub([head, ...tail.list], tail.alignment); } else { return head; } };
+  var peg$f16 = function(sc) { return sc; };
+  var peg$f17 = function(s) { return { name: "struct", args: { sequence:s }}};
+  var peg$f18 = function(s) { return { name: "target", args : { name:s}}};
+  var peg$f19 = function(p, s, r) { return { name: "bjorklund", args :{ pulse: parseInt(p), step:parseInt(s) }}};
+  var peg$f20 = function(a) { return { name: "stretch", args :{ amount: a}}};
+  var peg$f21 = function(a) { return { name: "shift", args :{ amount: "-"+a}}};
+  var peg$f22 = function(a) { return { name: "shift", args :{ amount: a}}};
+  var peg$f23 = function(a) { return { name: "stretch", args :{ amount: "1/"+a}}};
+  var peg$f24 = function(s) { return { name: "scale", args :{ scale: s.join("")}}};
+  var peg$f25 = function(s, v) { return v};
+  var peg$f26 = function(s, ss) { ss.unshift(s); return new PatternStub(ss,"t"); };
+  var peg$f27 = function(sg) {return sg};
+  var peg$f28 = function(o, soc) { return new OperatorStub(o.name,o.args,soc)};
+  var peg$f29 = function(sc) { return sc };
+  var peg$f30 = function(c) { return c };
+  var peg$f31 = function(v) { return new CommandStub("setcps", { value: v})};
+  var peg$f32 = function(v) { return new CommandStub("setcps", { value: (v/120/2)})};
+  var peg$f33 = function() { return new CommandStub("hush")};
   var peg$currPos = 0;
   var peg$savedPos = 0;
   var peg$posDetailsCache = [{ line: 1, column: 1 }];
@@ -734,23 +740,47 @@ function peg$parse(input, options) {
     return s0;
   }
 
+  function peg$parsepipe() {
+    var s0, s1, s2, s3;
+
+    s0 = peg$currPos;
+    s1 = peg$parsews();
+    if (input.charCodeAt(peg$currPos) === 124) {
+      s2 = peg$c5;
+      peg$currPos++;
+    } else {
+      s2 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e11); }
+    }
+    if (s2 !== peg$FAILED) {
+      s3 = peg$parsews();
+      s1 = [s1, s2, s3];
+      s0 = s1;
+    } else {
+      peg$currPos = s0;
+      s0 = peg$FAILED;
+    }
+
+    return s0;
+  }
+
   function peg$parsequote() {
     var s0;
 
     if (input.charCodeAt(peg$currPos) === 34) {
-      s0 = peg$c5;
+      s0 = peg$c6;
       peg$currPos++;
     } else {
       s0 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e11); }
+      if (peg$silentFails === 0) { peg$fail(peg$e12); }
     }
     if (s0 === peg$FAILED) {
       if (input.charCodeAt(peg$currPos) === 39) {
-        s0 = peg$c6;
+        s0 = peg$c7;
         peg$currPos++;
       } else {
         s0 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$e12); }
+        if (peg$silentFails === 0) { peg$fail(peg$e13); }
       }
     }
 
@@ -765,7 +795,7 @@ function peg$parse(input, options) {
       peg$currPos++;
     } else {
       s0 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e13); }
+      if (peg$silentFails === 0) { peg$fail(peg$e14); }
     }
     if (s0 === peg$FAILED) {
       if (input.charCodeAt(peg$currPos) === 45) {
@@ -777,11 +807,11 @@ function peg$parse(input, options) {
       }
       if (s0 === peg$FAILED) {
         if (input.charCodeAt(peg$currPos) === 35) {
-          s0 = peg$c7;
+          s0 = peg$c8;
           peg$currPos++;
         } else {
           s0 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$e14); }
+          if (peg$silentFails === 0) { peg$fail(peg$e15); }
         }
         if (s0 === peg$FAILED) {
           if (input.charCodeAt(peg$currPos) === 46) {
@@ -793,27 +823,27 @@ function peg$parse(input, options) {
           }
           if (s0 === peg$FAILED) {
             if (input.charCodeAt(peg$currPos) === 94) {
-              s0 = peg$c8;
+              s0 = peg$c9;
               peg$currPos++;
             } else {
               s0 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$e15); }
+              if (peg$silentFails === 0) { peg$fail(peg$e16); }
             }
             if (s0 === peg$FAILED) {
               if (input.charCodeAt(peg$currPos) === 95) {
-                s0 = peg$c9;
+                s0 = peg$c10;
                 peg$currPos++;
               } else {
                 s0 = peg$FAILED;
-                if (peg$silentFails === 0) { peg$fail(peg$e16); }
+                if (peg$silentFails === 0) { peg$fail(peg$e17); }
               }
               if (s0 === peg$FAILED) {
                 if (input.charCodeAt(peg$currPos) === 58) {
-                  s0 = peg$c10;
+                  s0 = peg$c11;
                   peg$currPos++;
                 } else {
                   s0 = peg$FAILED;
-                  if (peg$silentFails === 0) { peg$fail(peg$e17); }
+                  if (peg$silentFails === 0) { peg$fail(peg$e18); }
                 }
               }
             }
@@ -858,23 +888,23 @@ function peg$parse(input, options) {
     s0 = peg$currPos;
     s1 = peg$parsews();
     if (input.charCodeAt(peg$currPos) === 91) {
-      s2 = peg$c11;
+      s2 = peg$c12;
       peg$currPos++;
     } else {
       s2 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e18); }
+      if (peg$silentFails === 0) { peg$fail(peg$e19); }
     }
     if (s2 !== peg$FAILED) {
       s3 = peg$parsews();
-      s4 = peg$parsestack();
+      s4 = peg$parsestack_or_choose();
       if (s4 !== peg$FAILED) {
         s5 = peg$parsews();
         if (input.charCodeAt(peg$currPos) === 93) {
-          s6 = peg$c12;
+          s6 = peg$c13;
           peg$currPos++;
         } else {
           s6 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$e19); }
+          if (peg$silentFails === 0) { peg$fail(peg$e20); }
         }
         if (s6 !== peg$FAILED) {
           s7 = peg$parsews();
@@ -902,11 +932,11 @@ function peg$parse(input, options) {
     s0 = peg$currPos;
     s1 = peg$parsews();
     if (input.charCodeAt(peg$currPos) === 60) {
-      s2 = peg$c13;
+      s2 = peg$c14;
       peg$currPos++;
     } else {
       s2 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e20); }
+      if (peg$silentFails === 0) { peg$fail(peg$e21); }
     }
     if (s2 !== peg$FAILED) {
       s3 = peg$parsews();
@@ -914,11 +944,11 @@ function peg$parse(input, options) {
       if (s4 !== peg$FAILED) {
         s5 = peg$parsews();
         if (input.charCodeAt(peg$currPos) === 62) {
-          s6 = peg$c14;
+          s6 = peg$c15;
           peg$currPos++;
         } else {
           s6 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$e21); }
+          if (peg$silentFails === 0) { peg$fail(peg$e22); }
         }
         if (s6 !== peg$FAILED) {
           s7 = peg$parsews();
@@ -968,6 +998,9 @@ function peg$parse(input, options) {
             s0 = peg$parseslice_fixed_step();
             if (s0 === peg$FAILED) {
               s0 = peg$parseslice_replicate();
+              if (s0 === peg$FAILED) {
+                s0 = peg$parseslice_degrade();
+              }
             }
           }
         }
@@ -982,11 +1015,11 @@ function peg$parse(input, options) {
 
     s0 = peg$currPos;
     if (input.charCodeAt(peg$currPos) === 64) {
-      s1 = peg$c15;
+      s1 = peg$c16;
       peg$currPos++;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e22); }
+      if (peg$silentFails === 0) { peg$fail(peg$e23); }
     }
     if (s1 !== peg$FAILED) {
       s2 = peg$parsenumber();
@@ -1010,11 +1043,11 @@ function peg$parse(input, options) {
 
     s0 = peg$currPos;
     if (input.charCodeAt(peg$currPos) === 33) {
-      s1 = peg$c16;
+      s1 = peg$c17;
       peg$currPos++;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e23); }
+      if (peg$silentFails === 0) { peg$fail(peg$e24); }
     }
     if (s1 !== peg$FAILED) {
       s2 = peg$parsenumber();
@@ -1038,11 +1071,11 @@ function peg$parse(input, options) {
 
     s0 = peg$currPos;
     if (input.charCodeAt(peg$currPos) === 40) {
-      s1 = peg$c17;
+      s1 = peg$c18;
       peg$currPos++;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e24); }
+      if (peg$silentFails === 0) { peg$fail(peg$e25); }
     }
     if (s1 !== peg$FAILED) {
       s2 = peg$parsews();
@@ -1066,11 +1099,11 @@ function peg$parse(input, options) {
             }
             s12 = peg$parsews();
             if (input.charCodeAt(peg$currPos) === 41) {
-              s13 = peg$c18;
+              s13 = peg$c19;
               peg$currPos++;
             } else {
               s13 = peg$FAILED;
-              if (peg$silentFails === 0) { peg$fail(peg$e25); }
+              if (peg$silentFails === 0) { peg$fail(peg$e26); }
             }
             if (s13 !== peg$FAILED) {
               peg$savedPos = s0;
@@ -1104,11 +1137,11 @@ function peg$parse(input, options) {
 
     s0 = peg$currPos;
     if (input.charCodeAt(peg$currPos) === 47) {
-      s1 = peg$c19;
+      s1 = peg$c20;
       peg$currPos++;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e26); }
+      if (peg$silentFails === 0) { peg$fail(peg$e27); }
     }
     if (s1 !== peg$FAILED) {
       s2 = peg$parsenumber();
@@ -1132,11 +1165,11 @@ function peg$parse(input, options) {
 
     s0 = peg$currPos;
     if (input.charCodeAt(peg$currPos) === 42) {
-      s1 = peg$c20;
+      s1 = peg$c21;
       peg$currPos++;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e27); }
+      if (peg$silentFails === 0) { peg$fail(peg$e28); }
     }
     if (s1 !== peg$FAILED) {
       s2 = peg$parsenumber();
@@ -1160,11 +1193,11 @@ function peg$parse(input, options) {
 
     s0 = peg$currPos;
     if (input.charCodeAt(peg$currPos) === 37) {
-      s1 = peg$c21;
+      s1 = peg$c22;
       peg$currPos++;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e28); }
+      if (peg$silentFails === 0) { peg$fail(peg$e29); }
     }
     if (s1 !== peg$FAILED) {
       s2 = peg$parsenumber();
@@ -1183,6 +1216,32 @@ function peg$parse(input, options) {
     return s0;
   }
 
+  function peg$parseslice_degrade() {
+    var s0, s1, s2;
+
+    s0 = peg$currPos;
+    if (input.charCodeAt(peg$currPos) === 63) {
+      s1 = peg$c23;
+      peg$currPos++;
+    } else {
+      s1 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e30); }
+    }
+    if (s1 !== peg$FAILED) {
+      s2 = peg$parsenumber();
+      if (s2 === peg$FAILED) {
+        s2 = null;
+      }
+      peg$savedPos = s0;
+      s0 = peg$f10(s2);
+    } else {
+      peg$currPos = s0;
+      s0 = peg$FAILED;
+    }
+
+    return s0;
+  }
+
   function peg$parseslice_with_modifier() {
     var s0, s1, s2;
 
@@ -1194,7 +1253,7 @@ function peg$parse(input, options) {
         s2 = null;
       }
       peg$savedPos = s0;
-      s0 = peg$f10(s1, s2);
+      s0 = peg$f11(s1, s2);
     } else {
       peg$currPos = s0;
       s0 = peg$FAILED;
@@ -1219,55 +1278,126 @@ function peg$parse(input, options) {
     }
     if (s1 !== peg$FAILED) {
       peg$savedPos = s0;
-      s1 = peg$f11(s1);
+      s1 = peg$f12(s1);
     }
     s0 = s1;
 
     return s0;
   }
 
-  function peg$parsestack() {
-    var s0, s1, s2, s3, s4, s5;
+  function peg$parsestack_tail() {
+    var s0, s1, s2, s3, s4;
+
+    s0 = peg$currPos;
+    s1 = [];
+    s2 = peg$currPos;
+    s3 = peg$parsecomma();
+    if (s3 !== peg$FAILED) {
+      s4 = peg$parsesingle_cycle();
+      if (s4 !== peg$FAILED) {
+        s2 = s4;
+      } else {
+        peg$currPos = s2;
+        s2 = peg$FAILED;
+      }
+    } else {
+      peg$currPos = s2;
+      s2 = peg$FAILED;
+    }
+    if (s2 !== peg$FAILED) {
+      while (s2 !== peg$FAILED) {
+        s1.push(s2);
+        s2 = peg$currPos;
+        s3 = peg$parsecomma();
+        if (s3 !== peg$FAILED) {
+          s4 = peg$parsesingle_cycle();
+          if (s4 !== peg$FAILED) {
+            s2 = s4;
+          } else {
+            peg$currPos = s2;
+            s2 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s2;
+          s2 = peg$FAILED;
+        }
+      }
+    } else {
+      s1 = peg$FAILED;
+    }
+    if (s1 !== peg$FAILED) {
+      peg$savedPos = s0;
+      s1 = peg$f13(s1);
+    }
+    s0 = s1;
+
+    return s0;
+  }
+
+  function peg$parsechoose_tail() {
+    var s0, s1, s2, s3, s4;
+
+    s0 = peg$currPos;
+    s1 = [];
+    s2 = peg$currPos;
+    s3 = peg$parsepipe();
+    if (s3 !== peg$FAILED) {
+      s4 = peg$parsesingle_cycle();
+      if (s4 !== peg$FAILED) {
+        s2 = s4;
+      } else {
+        peg$currPos = s2;
+        s2 = peg$FAILED;
+      }
+    } else {
+      peg$currPos = s2;
+      s2 = peg$FAILED;
+    }
+    if (s2 !== peg$FAILED) {
+      while (s2 !== peg$FAILED) {
+        s1.push(s2);
+        s2 = peg$currPos;
+        s3 = peg$parsepipe();
+        if (s3 !== peg$FAILED) {
+          s4 = peg$parsesingle_cycle();
+          if (s4 !== peg$FAILED) {
+            s2 = s4;
+          } else {
+            peg$currPos = s2;
+            s2 = peg$FAILED;
+          }
+        } else {
+          peg$currPos = s2;
+          s2 = peg$FAILED;
+        }
+      }
+    } else {
+      s1 = peg$FAILED;
+    }
+    if (s1 !== peg$FAILED) {
+      peg$savedPos = s0;
+      s1 = peg$f14(s1);
+    }
+    s0 = s1;
+
+    return s0;
+  }
+
+  function peg$parsestack_or_choose() {
+    var s0, s1, s2;
 
     s0 = peg$currPos;
     s1 = peg$parsesingle_cycle();
     if (s1 !== peg$FAILED) {
-      s2 = [];
-      s3 = peg$currPos;
-      s4 = peg$parsecomma();
-      if (s4 !== peg$FAILED) {
-        s5 = peg$parsesingle_cycle();
-        if (s5 !== peg$FAILED) {
-          peg$savedPos = s3;
-          s3 = peg$f12(s1, s5);
-        } else {
-          peg$currPos = s3;
-          s3 = peg$FAILED;
-        }
-      } else {
-        peg$currPos = s3;
-        s3 = peg$FAILED;
+      s2 = peg$parsestack_tail();
+      if (s2 === peg$FAILED) {
+        s2 = peg$parsechoose_tail();
       }
-      while (s3 !== peg$FAILED) {
-        s2.push(s3);
-        s3 = peg$currPos;
-        s4 = peg$parsecomma();
-        if (s4 !== peg$FAILED) {
-          s5 = peg$parsesingle_cycle();
-          if (s5 !== peg$FAILED) {
-            peg$savedPos = s3;
-            s3 = peg$f12(s1, s5);
-          } else {
-            peg$currPos = s3;
-            s3 = peg$FAILED;
-          }
-        } else {
-          peg$currPos = s3;
-          s3 = peg$FAILED;
-        }
+      if (s2 === peg$FAILED) {
+        s2 = null;
       }
       peg$savedPos = s0;
-      s0 = peg$f13(s1, s2);
+      s0 = peg$f15(s1, s2);
     } else {
       peg$currPos = s0;
       s0 = peg$FAILED;
@@ -1283,12 +1413,12 @@ function peg$parse(input, options) {
     s1 = peg$parsews();
     s2 = peg$parsequote();
     if (s2 !== peg$FAILED) {
-      s3 = peg$parsestack();
+      s3 = peg$parsestack_or_choose();
       if (s3 !== peg$FAILED) {
         s4 = peg$parsequote();
         if (s4 !== peg$FAILED) {
           peg$savedPos = s0;
-          s0 = peg$f14(s3);
+          s0 = peg$f16(s3);
         } else {
           peg$currPos = s0;
           s0 = peg$FAILED;
@@ -1338,19 +1468,19 @@ function peg$parse(input, options) {
     var s0, s1, s2, s3;
 
     s0 = peg$currPos;
-    if (input.substr(peg$currPos, 6) === peg$c22) {
-      s1 = peg$c22;
+    if (input.substr(peg$currPos, 6) === peg$c24) {
+      s1 = peg$c24;
       peg$currPos += 6;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e29); }
+      if (peg$silentFails === 0) { peg$fail(peg$e31); }
     }
     if (s1 !== peg$FAILED) {
       s2 = peg$parsews();
       s3 = peg$parsesequence_or_operator();
       if (s3 !== peg$FAILED) {
         peg$savedPos = s0;
-        s0 = peg$f15(s3);
+        s0 = peg$f17(s3);
       } else {
         peg$currPos = s0;
         s0 = peg$FAILED;
@@ -1367,12 +1497,12 @@ function peg$parse(input, options) {
     var s0, s1, s2, s3, s4, s5;
 
     s0 = peg$currPos;
-    if (input.substr(peg$currPos, 6) === peg$c23) {
-      s1 = peg$c23;
+    if (input.substr(peg$currPos, 6) === peg$c25) {
+      s1 = peg$c25;
       peg$currPos += 6;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e30); }
+      if (peg$silentFails === 0) { peg$fail(peg$e32); }
     }
     if (s1 !== peg$FAILED) {
       s2 = peg$parsews();
@@ -1383,7 +1513,7 @@ function peg$parse(input, options) {
           s5 = peg$parsequote();
           if (s5 !== peg$FAILED) {
             peg$savedPos = s0;
-            s0 = peg$f16(s4);
+            s0 = peg$f18(s4);
           } else {
             peg$currPos = s0;
             s0 = peg$FAILED;
@@ -1408,12 +1538,12 @@ function peg$parse(input, options) {
     var s0, s1, s2, s3, s4, s5, s6, s7;
 
     s0 = peg$currPos;
-    if (input.substr(peg$currPos, 6) === peg$c24) {
-      s1 = peg$c24;
+    if (input.substr(peg$currPos, 6) === peg$c26) {
+      s1 = peg$c26;
       peg$currPos += 6;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e31); }
+      if (peg$silentFails === 0) { peg$fail(peg$e33); }
     }
     if (s1 !== peg$FAILED) {
       s2 = peg$parsews();
@@ -1428,7 +1558,7 @@ function peg$parse(input, options) {
             s7 = null;
           }
           peg$savedPos = s0;
-          s0 = peg$f17(s3, s5, s7);
+          s0 = peg$f19(s3, s5, s7);
         } else {
           peg$currPos = s0;
           s0 = peg$FAILED;
@@ -1448,64 +1578,6 @@ function peg$parse(input, options) {
   function peg$parseslow() {
     var s0, s1, s2, s3;
 
-    s0 = peg$currPos;
-    if (input.substr(peg$currPos, 4) === peg$c25) {
-      s1 = peg$c25;
-      peg$currPos += 4;
-    } else {
-      s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e32); }
-    }
-    if (s1 !== peg$FAILED) {
-      s2 = peg$parsews();
-      s3 = peg$parsenumber();
-      if (s3 !== peg$FAILED) {
-        peg$savedPos = s0;
-        s0 = peg$f18(s3);
-      } else {
-        peg$currPos = s0;
-        s0 = peg$FAILED;
-      }
-    } else {
-      peg$currPos = s0;
-      s0 = peg$FAILED;
-    }
-
-    return s0;
-  }
-
-  function peg$parserotL() {
-    var s0, s1, s2, s3;
-
-    s0 = peg$currPos;
-    if (input.substr(peg$currPos, 4) === peg$c26) {
-      s1 = peg$c26;
-      peg$currPos += 4;
-    } else {
-      s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e33); }
-    }
-    if (s1 !== peg$FAILED) {
-      s2 = peg$parsews();
-      s3 = peg$parsenumber();
-      if (s3 !== peg$FAILED) {
-        peg$savedPos = s0;
-        s0 = peg$f19(s3);
-      } else {
-        peg$currPos = s0;
-        s0 = peg$FAILED;
-      }
-    } else {
-      peg$currPos = s0;
-      s0 = peg$FAILED;
-    }
-
-    return s0;
-  }
-
-  function peg$parserotR() {
-    var s0, s1, s2, s3;
-
     s0 = peg$currPos;
     if (input.substr(peg$currPos, 4) === peg$c27) {
       s1 = peg$c27;
@@ -1532,7 +1604,7 @@ function peg$parse(input, options) {
     return s0;
   }
 
-  function peg$parsefast() {
+  function peg$parserotL() {
     var s0, s1, s2, s3;
 
     s0 = peg$currPos;
@@ -1561,16 +1633,74 @@ function peg$parse(input, options) {
     return s0;
   }
 
+  function peg$parserotR() {
+    var s0, s1, s2, s3;
+
+    s0 = peg$currPos;
+    if (input.substr(peg$currPos, 4) === peg$c29) {
+      s1 = peg$c29;
+      peg$currPos += 4;
+    } else {
+      s1 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e36); }
+    }
+    if (s1 !== peg$FAILED) {
+      s2 = peg$parsews();
+      s3 = peg$parsenumber();
+      if (s3 !== peg$FAILED) {
+        peg$savedPos = s0;
+        s0 = peg$f22(s3);
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+    } else {
+      peg$currPos = s0;
+      s0 = peg$FAILED;
+    }
+
+    return s0;
+  }
+
+  function peg$parsefast() {
+    var s0, s1, s2, s3;
+
+    s0 = peg$currPos;
+    if (input.substr(peg$currPos, 4) === peg$c30) {
+      s1 = peg$c30;
+      peg$currPos += 4;
+    } else {
+      s1 = peg$FAILED;
+      if (peg$silentFails === 0) { peg$fail(peg$e37); }
+    }
+    if (s1 !== peg$FAILED) {
+      s2 = peg$parsews();
+      s3 = peg$parsenumber();
+      if (s3 !== peg$FAILED) {
+        peg$savedPos = s0;
+        s0 = peg$f23(s3);
+      } else {
+        peg$currPos = s0;
+        s0 = peg$FAILED;
+      }
+    } else {
+      peg$currPos = s0;
+      s0 = peg$FAILED;
+    }
+
+    return s0;
+  }
+
   function peg$parsescale() {
     var s0, s1, s2, s3, s4, s5;
 
     s0 = peg$currPos;
-    if (input.substr(peg$currPos, 5) === peg$c29) {
-      s1 = peg$c29;
+    if (input.substr(peg$currPos, 5) === peg$c31) {
+      s1 = peg$c31;
       peg$currPos += 5;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e36); }
+      if (peg$silentFails === 0) { peg$fail(peg$e38); }
     }
     if (s1 !== peg$FAILED) {
       s2 = peg$parsews();
@@ -1590,7 +1720,7 @@ function peg$parse(input, options) {
           s5 = peg$parsequote();
           if (s5 !== peg$FAILED) {
             peg$savedPos = s0;
-            s0 = peg$f22(s4);
+            s0 = peg$f24(s4);
           } else {
             peg$currPos = s0;
             s0 = peg$FAILED;
@@ -1615,12 +1745,12 @@ function peg$parse(input, options) {
     var s0, s1, s2, s3;
 
     s0 = peg$currPos;
-    if (input.substr(peg$currPos, 2) === peg$c30) {
-      s1 = peg$c30;
+    if (input.substr(peg$currPos, 2) === peg$c32) {
+      s1 = peg$c32;
       peg$currPos += 2;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e37); }
+      if (peg$silentFails === 0) { peg$fail(peg$e39); }
     }
     if (s1 !== peg$FAILED) {
       s2 = [];
@@ -1629,7 +1759,7 @@ function peg$parse(input, options) {
         peg$currPos++;
       } else {
         s3 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$e38); }
+        if (peg$silentFails === 0) { peg$fail(peg$e40); }
       }
       while (s3 !== peg$FAILED) {
         s2.push(s3);
@@ -1638,7 +1768,7 @@ function peg$parse(input, options) {
           peg$currPos++;
         } else {
           s3 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$e38); }
+          if (peg$silentFails === 0) { peg$fail(peg$e40); }
         }
       }
       s1 = [s1, s2];
@@ -1655,21 +1785,21 @@ function peg$parse(input, options) {
     var s0, s1, s2, s3, s4, s5, s6, s7, s8, s9;
 
     s0 = peg$currPos;
-    if (input.substr(peg$currPos, 3) === peg$c31) {
-      s1 = peg$c31;
+    if (input.substr(peg$currPos, 3) === peg$c33) {
+      s1 = peg$c33;
       peg$currPos += 3;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e39); }
+      if (peg$silentFails === 0) { peg$fail(peg$e41); }
     }
     if (s1 !== peg$FAILED) {
       s2 = peg$parsews();
       if (input.charCodeAt(peg$currPos) === 91) {
-        s3 = peg$c11;
+        s3 = peg$c12;
         peg$currPos++;
       } else {
         s3 = peg$FAILED;
-        if (peg$silentFails === 0) { peg$fail(peg$e18); }
+        if (peg$silentFails === 0) { peg$fail(peg$e19); }
       }
       if (s3 !== peg$FAILED) {
         s4 = peg$parsews();
@@ -1682,7 +1812,7 @@ function peg$parse(input, options) {
             s9 = peg$parsesequence_or_operator();
             if (s9 !== peg$FAILED) {
               peg$savedPos = s7;
-              s7 = peg$f23(s5, s9);
+              s7 = peg$f25(s5, s9);
             } else {
               peg$currPos = s7;
               s7 = peg$FAILED;
@@ -1699,7 +1829,7 @@ function peg$parse(input, options) {
               s9 = peg$parsesequence_or_operator();
               if (s9 !== peg$FAILED) {
                 peg$savedPos = s7;
-                s7 = peg$f23(s5, s9);
+                s7 = peg$f25(s5, s9);
               } else {
                 peg$currPos = s7;
                 s7 = peg$FAILED;
@@ -1711,15 +1841,15 @@ function peg$parse(input, options) {
           }
           s7 = peg$parsews();
           if (input.charCodeAt(peg$currPos) === 93) {
-            s8 = peg$c12;
+            s8 = peg$c13;
             peg$currPos++;
           } else {
             s8 = peg$FAILED;
-            if (peg$silentFails === 0) { peg$fail(peg$e19); }
+            if (peg$silentFails === 0) { peg$fail(peg$e20); }
           }
           if (s8 !== peg$FAILED) {
             peg$savedPos = s0;
-            s0 = peg$f24(s5, s6);
+            s0 = peg$f26(s5, s6);
           } else {
             peg$currPos = s0;
             s0 = peg$FAILED;
@@ -1765,7 +1895,7 @@ function peg$parse(input, options) {
         s4 = peg$parsecomment();
       }
       peg$savedPos = s0;
-      s0 = peg$f25(s1);
+      s0 = peg$f27(s1);
     } else {
       peg$currPos = s0;
       s0 = peg$FAILED;
@@ -1776,18 +1906,18 @@ function peg$parse(input, options) {
       if (s1 !== peg$FAILED) {
         s2 = peg$parsews();
         if (input.charCodeAt(peg$currPos) === 36) {
-          s3 = peg$c32;
+          s3 = peg$c34;
           peg$currPos++;
         } else {
           s3 = peg$FAILED;
-          if (peg$silentFails === 0) { peg$fail(peg$e40); }
+          if (peg$silentFails === 0) { peg$fail(peg$e42); }
         }
         if (s3 !== peg$FAILED) {
           s4 = peg$parsews();
           s5 = peg$parsesequence_or_operator();
           if (s5 !== peg$FAILED) {
             peg$savedPos = s0;
-            s0 = peg$f26(s1, s5);
+            s0 = peg$f28(s1, s5);
           } else {
             peg$currPos = s0;
             s0 = peg$FAILED;
@@ -1812,7 +1942,7 @@ function peg$parse(input, options) {
     s1 = peg$parsesequence_or_operator();
     if (s1 !== peg$FAILED) {
       peg$savedPos = s0;
-      s1 = peg$f27(s1);
+      s1 = peg$f29(s1);
     }
     s0 = s1;
     if (s0 === peg$FAILED) {
@@ -1845,7 +1975,7 @@ function peg$parse(input, options) {
     if (s2 !== peg$FAILED) {
       s3 = peg$parsews();
       peg$savedPos = s0;
-      s0 = peg$f28(s2);
+      s0 = peg$f30(s2);
     } else {
       peg$currPos = s0;
       s0 = peg$FAILED;
@@ -1858,19 +1988,19 @@ function peg$parse(input, options) {
     var s0, s1, s2, s3;
 
     s0 = peg$currPos;
-    if (input.substr(peg$currPos, 6) === peg$c33) {
-      s1 = peg$c33;
+    if (input.substr(peg$currPos, 6) === peg$c35) {
+      s1 = peg$c35;
       peg$currPos += 6;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e41); }
+      if (peg$silentFails === 0) { peg$fail(peg$e43); }
     }
     if (s1 !== peg$FAILED) {
       s2 = peg$parsews();
       s3 = peg$parsenumber();
       if (s3 !== peg$FAILED) {
         peg$savedPos = s0;
-        s0 = peg$f29(s3);
+        s0 = peg$f31(s3);
       } else {
         peg$currPos = s0;
         s0 = peg$FAILED;
@@ -1887,19 +2017,19 @@ function peg$parse(input, options) {
     var s0, s1, s2, s3;
 
     s0 = peg$currPos;
-    if (input.substr(peg$currPos, 6) === peg$c34) {
-      s1 = peg$c34;
+    if (input.substr(peg$currPos, 6) === peg$c36) {
+      s1 = peg$c36;
       peg$currPos += 6;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e42); }
+      if (peg$silentFails === 0) { peg$fail(peg$e44); }
     }
     if (s1 !== peg$FAILED) {
       s2 = peg$parsews();
       s3 = peg$parsenumber();
       if (s3 !== peg$FAILED) {
         peg$savedPos = s0;
-        s0 = peg$f30(s3);
+        s0 = peg$f32(s3);
       } else {
         peg$currPos = s0;
         s0 = peg$FAILED;
@@ -1916,16 +2046,16 @@ function peg$parse(input, options) {
     var s0, s1;
 
     s0 = peg$currPos;
-    if (input.substr(peg$currPos, 4) === peg$c35) {
-      s1 = peg$c35;
+    if (input.substr(peg$currPos, 4) === peg$c37) {
+      s1 = peg$c37;
       peg$currPos += 4;
     } else {
       s1 = peg$FAILED;
-      if (peg$silentFails === 0) { peg$fail(peg$e43); }
+      if (peg$silentFails === 0) { peg$fail(peg$e45); }
     }
     if (s1 !== peg$FAILED) {
       peg$savedPos = s0;
-      s1 = peg$f31();
+      s1 = peg$f33();
     }
     s0 = s1;