diff --git a/ldtext/LDText.fs b/ldtext/LDText.fs
index 08b29fd..3f9880b 100644
--- a/ldtext/LDText.fs
+++ b/ldtext/LDText.fs
@@ -1,13 +1,20 @@
 module LDText
 
 module Ast =
-    type Rung = Step list
+    type Rung =
+        | Rung of Step list
 
     and Instr = { Op: string; Args: Operand list }
 
+    and BranchArm =
+        | BranchArm of Step list
+
+    and Branch =
+        | Branch of BranchArm list
+
     and Step =
         | StepInstr of Instr
-        | StepBranch of Step list
+        | StepBranch of Branch
 
     and Operand =
         | OperandHole
diff --git a/ldtext/Parser.fs b/ldtext/Parser.fs
index 99f21c9..d6ba291 100644
--- a/ldtext/Parser.fs
+++ b/ldtext/Parser.fs
@@ -38,6 +38,8 @@ type nonTerminalId =
     | NONTERM__startrung
     | NONTERM_rung
     | NONTERM_steps
+    | NONTERM_branch
+    | NONTERM_branch_arms
     | NONTERM_instr
     | NONTERM_operands
     | NONTERM_operand
@@ -78,12 +80,17 @@ let prodIdxToNonTerminal (prodIdx:int) =
     | 1 -> NONTERM_rung 
     | 2 -> NONTERM_steps 
     | 3 -> NONTERM_steps 
-    | 4 -> NONTERM_instr 
-    | 5 -> NONTERM_operands 
-    | 6 -> NONTERM_operands 
-    | 7 -> NONTERM_operands 
-    | 8 -> NONTERM_operand 
-    | 9 -> NONTERM_operand 
+    | 4 -> NONTERM_steps 
+    | 5 -> NONTERM_branch 
+    | 6 -> NONTERM_branch_arms 
+    | 7 -> NONTERM_branch_arms 
+    | 8 -> NONTERM_branch_arms 
+    | 9 -> NONTERM_instr 
+    | 10 -> NONTERM_operands 
+    | 11 -> NONTERM_operands 
+    | 12 -> NONTERM_operands 
+    | 13 -> NONTERM_operand 
+    | 14 -> NONTERM_operand 
     | _ -> failwith "prodIdxToNonTerminal: bad production index"
 
 let _fsyacc_endOfInputTag = 11 
@@ -114,38 +121,38 @@ let _fsyacc_dataOfToken (t:token) =
   | RIGHT_PAREN  -> (null : System.Object) 
   | LEFT_PAREN  -> (null : System.Object) 
   | IDENTIFIER _fsyacc_x -> Microsoft.FSharp.Core.Operators.box _fsyacc_x 
-let _fsyacc_gotos = [| 0us;65535us;1us;65535us;0us;1us;2us;65535us;0us;2us;5us;6us;2us;65535us;0us;5us;5us;5us;2us;65535us;8us;9us;12us;13us;2us;65535us;8us;11us;12us;11us;|]
-let _fsyacc_sparseGotoTableRowOffsets = [|0us;1us;3us;6us;9us;12us;|]
-let _fsyacc_stateToProdIdxsTableElements = [| 1us;0us;1us;0us;1us;1us;1us;1us;1us;1us;1us;3us;1us;3us;1us;4us;1us;4us;1us;4us;1us;4us;2us;6us;7us;1us;6us;1us;6us;1us;8us;1us;9us;|]
-let _fsyacc_stateToProdIdxsTableRowOffsets = [|0us;2us;4us;6us;8us;10us;12us;14us;16us;18us;20us;22us;25us;27us;29us;31us;|]
-let _fsyacc_action_rows = 16
-let _fsyacc_actionTableElements = [|1us;16386us;8us;7us;0us;49152us;1us;32768us;2us;3us;1us;32768us;0us;4us;0us;16385us;1us;16386us;8us;7us;0us;16387us;1us;32768us;7us;8us;2us;16389us;1us;15us;8us;14us;1us;32768us;6us;10us;0us;16388us;1us;16391us;3us;12us;2us;16389us;1us;15us;8us;14us;0us;16390us;0us;16392us;0us;16393us;|]
-let _fsyacc_actionTableRowOffsets = [|0us;2us;3us;5us;7us;8us;10us;11us;13us;16us;18us;19us;21us;24us;25us;26us;|]
-let _fsyacc_reductionSymbolCounts = [|1us;3us;0us;2us;4us;0us;3us;1us;1us;1us;|]
-let _fsyacc_productionToNonTerminalTable = [|0us;1us;2us;2us;3us;4us;4us;4us;5us;5us;|]
-let _fsyacc_immediateActions = [|65535us;49152us;65535us;65535us;16385us;65535us;16387us;65535us;65535us;65535us;16388us;65535us;65535us;16390us;16392us;16393us;|]
+let _fsyacc_gotos = [| 0us;65535us;1us;65535us;0us;1us;5us;65535us;0us;2us;5us;6us;7us;8us;9us;12us;13us;12us;5us;65535us;0us;7us;5us;7us;7us;7us;9us;7us;13us;7us;2us;65535us;9us;10us;13us;14us;5us;65535us;0us;5us;5us;5us;7us;5us;9us;5us;13us;5us;2us;65535us;16us;17us;20us;21us;2us;65535us;16us;19us;20us;19us;|]
+let _fsyacc_sparseGotoTableRowOffsets = [|0us;1us;3us;9us;15us;18us;24us;27us;|]
+let _fsyacc_stateToProdIdxsTableElements = [| 1us;0us;1us;0us;1us;1us;1us;1us;1us;1us;1us;3us;1us;3us;1us;4us;1us;4us;1us;5us;1us;5us;1us;5us;2us;7us;8us;1us;7us;1us;7us;1us;9us;1us;9us;1us;9us;1us;9us;2us;11us;12us;1us;11us;1us;11us;1us;13us;1us;14us;|]
+let _fsyacc_stateToProdIdxsTableRowOffsets = [|0us;2us;4us;6us;8us;10us;12us;14us;16us;18us;20us;22us;24us;27us;29us;31us;33us;35us;37us;39us;42us;44us;46us;48us;|]
+let _fsyacc_action_rows = 24
+let _fsyacc_actionTableElements = [|2us;16386us;5us;9us;8us;15us;0us;49152us;1us;32768us;2us;3us;1us;32768us;0us;4us;0us;16385us;2us;16386us;5us;9us;8us;15us;0us;16387us;2us;16386us;5us;9us;8us;15us;0us;16388us;2us;16386us;5us;9us;8us;15us;1us;32768us;4us;11us;0us;16389us;1us;16392us;3us;13us;2us;16386us;5us;9us;8us;15us;0us;16391us;1us;32768us;7us;16us;2us;16394us;1us;23us;8us;22us;1us;32768us;6us;18us;0us;16393us;1us;16396us;3us;20us;2us;16394us;1us;23us;8us;22us;0us;16395us;0us;16397us;0us;16398us;|]
+let _fsyacc_actionTableRowOffsets = [|0us;3us;4us;6us;8us;9us;12us;13us;16us;17us;20us;22us;23us;25us;28us;29us;31us;34us;36us;37us;39us;42us;43us;44us;|]
+let _fsyacc_reductionSymbolCounts = [|1us;3us;0us;2us;2us;3us;0us;3us;1us;4us;0us;3us;1us;1us;1us;|]
+let _fsyacc_productionToNonTerminalTable = [|0us;1us;2us;2us;2us;3us;4us;4us;4us;5us;6us;6us;6us;7us;7us;|]
+let _fsyacc_immediateActions = [|65535us;49152us;65535us;65535us;16385us;65535us;16387us;65535us;16388us;65535us;65535us;16389us;65535us;65535us;16391us;65535us;65535us;65535us;16393us;65535us;65535us;16395us;16397us;16398us;|]
 let _fsyacc_reductions = lazy [|
-# 128 "Parser.fs"
+# 135 "Parser.fs"
         (fun (parseState : FSharp.Text.Parsing.IParseState) ->
-            let _1 = parseState.GetInput(1) :?> Instr list in
+            let _1 = parseState.GetInput(1) :?> Rung in
             Microsoft.FSharp.Core.Operators.box
                 (
                    (
                       raise (FSharp.Text.Parsing.Accept(Microsoft.FSharp.Core.Operators.box _1))
                    )
                  : 'gentype__startrung));
-# 137 "Parser.fs"
+# 144 "Parser.fs"
         (fun (parseState : FSharp.Text.Parsing.IParseState) ->
             let _1 = parseState.GetInput(1) :?> 'gentype_steps in
             Microsoft.FSharp.Core.Operators.box
                 (
                    (
 # 26 "Parser.fsy"
-                                               _1 
+                                               Rung _1 
                    )
 # 26 "Parser.fsy"
-                 : Instr list));
-# 148 "Parser.fs"
+                 : Rung));
+# 155 "Parser.fs"
         (fun (parseState : FSharp.Text.Parsing.IParseState) ->
             Microsoft.FSharp.Core.Operators.box
                 (
@@ -155,7 +162,7 @@ let _fsyacc_reductions = lazy [|
                    )
 # 29 "Parser.fsy"
                  : 'gentype_steps));
-# 158 "Parser.fs"
+# 165 "Parser.fs"
         (fun (parseState : FSharp.Text.Parsing.IParseState) ->
             let _1 = parseState.GetInput(1) :?> 'gentype_instr in
             let _2 = parseState.GetInput(2) :?> 'gentype_steps in
@@ -163,78 +170,134 @@ let _fsyacc_reductions = lazy [|
                 (
                    (
 # 30 "Parser.fsy"
-                                       _1 :: _2 
+                                       StepInstr _1 :: _2 
                    )
 # 30 "Parser.fsy"
                  : 'gentype_steps));
-# 170 "Parser.fs"
+# 177 "Parser.fs"
         (fun (parseState : FSharp.Text.Parsing.IParseState) ->
-            let _1 = parseState.GetInput(1) :?> string in
-            let _3 = parseState.GetInput(3) :?> 'gentype_operands in
+            let _1 = parseState.GetInput(1) :?> 'gentype_branch in
+            let _2 = parseState.GetInput(2) :?> 'gentype_steps in
             Microsoft.FSharp.Core.Operators.box
                 (
                    (
-# 33 "Parser.fsy"
-                                                                      { Op = _1; Args = _3 } 
+# 31 "Parser.fsy"
+                                        StepBranch _1 :: _2 
                    )
-# 33 "Parser.fsy"
-                 : 'gentype_instr));
-# 182 "Parser.fs"
+# 31 "Parser.fsy"
+                 : 'gentype_steps));
+# 189 "Parser.fs"
+        (fun (parseState : FSharp.Text.Parsing.IParseState) ->
+            let _2 = parseState.GetInput(2) :?> 'gentype_branch_arms in
+            Microsoft.FSharp.Core.Operators.box
+                (
+                   (
+# 34 "Parser.fsy"
+                                                                  Branch _2 
+                   )
+# 34 "Parser.fsy"
+                 : 'gentype_branch));
+# 200 "Parser.fs"
         (fun (parseState : FSharp.Text.Parsing.IParseState) ->
             Microsoft.FSharp.Core.Operators.box
                 (
                    (
-# 36 "Parser.fsy"
+# 37 "Parser.fsy"
                            [] 
                    )
-# 36 "Parser.fsy"
+# 37 "Parser.fsy"
+                 : 'gentype_branch_arms));
+# 210 "Parser.fs"
+        (fun (parseState : FSharp.Text.Parsing.IParseState) ->
+            let _1 = parseState.GetInput(1) :?> 'gentype_steps in
+            let _3 = parseState.GetInput(3) :?> 'gentype_branch_arms in
+            Microsoft.FSharp.Core.Operators.box
+                (
+                   (
+# 38 "Parser.fsy"
+                                                   BranchArm _1 :: _3
+                   )
+# 38 "Parser.fsy"
+                 : 'gentype_branch_arms));
+# 222 "Parser.fs"
+        (fun (parseState : FSharp.Text.Parsing.IParseState) ->
+            let _1 = parseState.GetInput(1) :?> 'gentype_steps in
+            Microsoft.FSharp.Core.Operators.box
+                (
+                   (
+# 39 "Parser.fsy"
+                                 [ BranchArm _1 ] 
+                   )
+# 39 "Parser.fsy"
+                 : 'gentype_branch_arms));
+# 233 "Parser.fs"
+        (fun (parseState : FSharp.Text.Parsing.IParseState) ->
+            let _1 = parseState.GetInput(1) :?> string in
+            let _3 = parseState.GetInput(3) :?> 'gentype_operands in
+            Microsoft.FSharp.Core.Operators.box
+                (
+                   (
+# 42 "Parser.fsy"
+                                                                      { Op = _1; Args = _3 } 
+                   )
+# 42 "Parser.fsy"
+                 : 'gentype_instr));
+# 245 "Parser.fs"
+        (fun (parseState : FSharp.Text.Parsing.IParseState) ->
+            Microsoft.FSharp.Core.Operators.box
+                (
+                   (
+# 45 "Parser.fsy"
+                           [] 
+                   )
+# 45 "Parser.fsy"
                  : 'gentype_operands));
-# 192 "Parser.fs"
+# 255 "Parser.fs"
         (fun (parseState : FSharp.Text.Parsing.IParseState) ->
             let _1 = parseState.GetInput(1) :?> 'gentype_operand in
             let _3 = parseState.GetInput(3) :?> 'gentype_operands in
             Microsoft.FSharp.Core.Operators.box
                 (
                    (
-# 37 "Parser.fsy"
+# 46 "Parser.fsy"
                                                   _1 :: _3 
                    )
-# 37 "Parser.fsy"
+# 46 "Parser.fsy"
                  : 'gentype_operands));
-# 204 "Parser.fs"
+# 267 "Parser.fs"
         (fun (parseState : FSharp.Text.Parsing.IParseState) ->
             let _1 = parseState.GetInput(1) :?> 'gentype_operand in
             Microsoft.FSharp.Core.Operators.box
                 (
                    (
-# 38 "Parser.fsy"
+# 47 "Parser.fsy"
                                    [ _1 ] 
                    )
-# 38 "Parser.fsy"
+# 47 "Parser.fsy"
                  : 'gentype_operands));
-# 215 "Parser.fs"
+# 278 "Parser.fs"
         (fun (parseState : FSharp.Text.Parsing.IParseState) ->
             let _1 = parseState.GetInput(1) :?> string in
             Microsoft.FSharp.Core.Operators.box
                 (
                    (
-# 41 "Parser.fsy"
+# 50 "Parser.fsy"
                                       OperandTag _1 
                    )
-# 41 "Parser.fsy"
+# 50 "Parser.fsy"
                  : 'gentype_operand));
-# 226 "Parser.fs"
+# 289 "Parser.fs"
         (fun (parseState : FSharp.Text.Parsing.IParseState) ->
             Microsoft.FSharp.Core.Operators.box
                 (
                    (
-# 42 "Parser.fsy"
+# 51 "Parser.fsy"
                                          OperandHole 
                    )
-# 42 "Parser.fsy"
+# 51 "Parser.fsy"
                  : 'gentype_operand));
 |]
-# 237 "Parser.fs"
+# 300 "Parser.fs"
 let tables : FSharp.Text.Parsing.Tables<_> = 
   { reductions = _fsyacc_reductions.Value;
     endOfInputTag = _fsyacc_endOfInputTag;
@@ -256,5 +319,5 @@ let tables : FSharp.Text.Parsing.Tables<_> =
     numTerminals = 12;
     productionToNonTerminalTable = _fsyacc_productionToNonTerminalTable  }
 let engine lexer lexbuf startState = tables.Interpret(lexer, lexbuf, startState)
-let rung lexer lexbuf : Instr list =
+let rung lexer lexbuf : Rung =
     engine lexer lexbuf 0 :?> _
diff --git a/ldtext/Parser.fsi b/ldtext/Parser.fsi
index 19a1d95..334e3ce 100644
--- a/ldtext/Parser.fsi
+++ b/ldtext/Parser.fsi
@@ -26,6 +26,8 @@ type nonTerminalId =
     | NONTERM__startrung
     | NONTERM_rung
     | NONTERM_steps
+    | NONTERM_branch
+    | NONTERM_branch_arms
     | NONTERM_instr
     | NONTERM_operands
     | NONTERM_operand
@@ -40,4 +42,4 @@ val prodIdxToNonTerminal: int -> nonTerminalId
 
 /// This function gets the name of a token as a string
 val token_to_string: token -> string
-val rung : (FSharp.Text.Lexing.LexBuffer<'cty> -> token) -> FSharp.Text.Lexing.LexBuffer<'cty> -> (Instr list) 
+val rung : (FSharp.Text.Lexing.LexBuffer<'cty> -> token) -> FSharp.Text.Lexing.LexBuffer<'cty> -> (Rung) 
diff --git a/ldtext/Parser.fsy b/ldtext/Parser.fsy
index 971bad6..e2a50d3 100644
--- a/ldtext/Parser.fsy
+++ b/ldtext/Parser.fsy
@@ -18,16 +18,25 @@ open FSharp.Text.Lexing
 %start rung
 
 // return type of parser, marked by start token
-%type <Instr list> rung
+%type <Rung> rung
 
 %%
 
 rung:
-  | steps SEMICOLON EOF { $1 }
+  | steps SEMICOLON EOF { Rung $1 }
 
 steps:
   | { [] }
-  | instr steps { $1 :: $2 }
+  | instr steps { StepInstr $1 :: $2 }
+  | branch steps { StepBranch $1 :: $2 }
+
+branch:
+  | LEFT_BRACKET branch_arms RIGHT_BRACKET { Branch $2 }
+
+branch_arms:
+  | { [] }
+  | steps COMMA branch_arms { BranchArm $1 :: $3}
+  | steps { [ BranchArm $1 ] }
 
 instr:
   | IDENTIFIER LEFT_PAREN operands RIGHT_PAREN { { Op = $1; Args = $3 } }
diff --git a/ldtext/test.fsx b/ldtext/test.fsx
index d06074c..bfc7f19 100644
--- a/ldtext/test.fsx
+++ b/ldtext/test.fsx
@@ -22,5 +22,6 @@ parse "abc();"
 parse "abc(def);"
 parse "abc(def,ghi);"
 parse "abc(def,ghi) a(b) ;"
+parse "a() [ b() c(), d(), , e() [ f() ] g() ] h();"
 
 if failed then exit 1 else exit 0
\ No newline at end of file