diff --git a/TODO.md b/TODO.md
index 17e0da42..82abaf61 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,4 +1,7 @@
-remove `begin end` syntax
+top level env has checking -- for top level `Compose`
+
+- begin-type.error.i
+- begin-type-nested.error.i
 
 # books
 
diff --git a/src/lang/stmts/Begin.ts b/src/lang/stmts/Begin.ts
deleted file mode 100644
index 1aa67082..00000000
--- a/src/lang/stmts/Begin.ts
+++ /dev/null
@@ -1,32 +0,0 @@
-import { createChecking } from "../checking/createChecking"
-import { composeWords } from "../compose/composeWords"
-import { createEnv } from "../env/createEnv"
-import { appendReport } from "../errors/appendReport"
-import { Mod } from "../mod"
-import { Span } from "../span"
-import { Stmt } from "../stmt"
-import { Word } from "../word"
-
-export class Begin implements Stmt {
-  constructor(
-    public words: Array<Word>,
-    public span: Span,
-  ) {}
-
-  async execute(mod: Mod): Promise<void> {
-    try {
-      const env = createEnv(mod)
-      composeWords(mod, env, this.words, {
-        checking: createChecking(),
-      })
-    } catch (error) {
-      throw appendReport(error, {
-        message: `[Begin.execute] I fail to begin.`,
-        context: {
-          span: this.span,
-          text: mod.text,
-        },
-      })
-    }
-  }
-}
diff --git a/src/lang/stmts/index.ts b/src/lang/stmts/index.ts
index f30e0e35..ef15f0c4 100644
--- a/src/lang/stmts/index.ts
+++ b/src/lang/stmts/index.ts
@@ -1,4 +1,3 @@
-export * from "./Begin"
 export * from "./Check"
 export * from "./Claim"
 export * from "./Compose"
diff --git a/src/lang/syntax/grammars/name.ts b/src/lang/syntax/grammars/name.ts
index f850c304..b85ccf96 100644
--- a/src/lang/syntax/grammars/name.ts
+++ b/src/lang/syntax/grammars/name.ts
@@ -3,7 +3,7 @@
 const preserved = [
   ...["define", "claim"],
   ...["type", "node", "rule"],
-  ...["begin", "check"],
+  ...["check"],
   ...["import", "require"],
   ...["end"],
 ]
diff --git a/src/lang/syntax/grammars/stmt.ts b/src/lang/syntax/grammars/stmt.ts
index af1fcbfe..70f0ea79 100644
--- a/src/lang/syntax/grammars/stmt.ts
+++ b/src/lang/syntax/grammars/stmt.ts
@@ -37,7 +37,6 @@ export const stmt = {
       { output: "words" },
       '"end"',
     ],
-    "stmt:begin": ['"begin"', { words: "words" }, '"end"'],
     "stmt:check": [
       '"check"',
       { input: "words" },
diff --git a/src/lang/syntax/matchers/stmt_matcher.ts b/src/lang/syntax/matchers/stmt_matcher.ts
index ded910a2..203abd08 100644
--- a/src/lang/syntax/matchers/stmt_matcher.ts
+++ b/src/lang/syntax/matchers/stmt_matcher.ts
@@ -35,8 +35,6 @@ export function stmt_matcher(tree: pt.Tree): Stmt {
         matchers.words_matcher(output),
         span,
       ),
-    "stmt:begin": ({ words }, { span }) =>
-      new Stmts.Begin(matchers.words_matcher(words), span),
     "stmt:check": ({ input, output, words }, { span }) =>
       new Stmts.Check(
         matchers.words_matcher(input),
diff --git a/tests/builtin/connect-args.error.i b/tests/builtin/connect-args.error.i
index 7e9386f5..59302ee2 100644
--- a/tests/builtin/connect-args.error.i
+++ b/tests/builtin/connect-args.error.i
@@ -1,4 +1,4 @@
 type Trivial -- Type end
 node sole -- Trivial :value! end
 
-begin sole connect end
+sole connect
diff --git a/tests/builtin/connect-args.error.i.err b/tests/builtin/connect-args.error.i.err
index a8c203fb..ee3738a7 100644
--- a/tests/builtin/connect-args.error.i.err
+++ b/tests/builtin/connect-args.error.i.err
@@ -9,13 +9,15 @@
  1 |type Trivial -- Type end
  2 |node sole -- Trivial :value! end
  3 |
- 4 |begin sole connect end
+ 4 |sole connect
  5 |
 
-[Begin.execute] I fail to begin.
+[Compose.execute] I fail to compose word.
+
+  word: connect
 
  1 |type Trivial -- Type end
  2 |node sole -- Trivial :value! end
  3 |
- 4 |begin sole connect end
+ 4 |sole connect
  5 |
diff --git a/tests/builtin/inspect-args.error.i b/tests/builtin/inspect-args.error.i
index 955fcaa6..7c85ca2f 100644
--- a/tests/builtin/inspect-args.error.i
+++ b/tests/builtin/inspect-args.error.i
@@ -1 +1 @@
-begin inspect end
+inspect
diff --git a/tests/builtin/inspect-args.error.i.err b/tests/builtin/inspect-args.error.i.err
index 27d81fe8..95de7c33 100644
--- a/tests/builtin/inspect-args.error.i.err
+++ b/tests/builtin/inspect-args.error.i.err
@@ -4,10 +4,12 @@
 
   word: inspect
 
- 1 |begin inspect end
+ 1 |inspect
  2 |
 
-[Begin.execute] I fail to begin.
+[Compose.execute] I fail to compose word.
 
- 1 |begin inspect end
+  word: inspect
+
+ 1 |inspect
  2 |
diff --git a/tests/builtin/rot-args.error.i b/tests/builtin/rot-args.error.i
index a09d8fc9..36c636f1 100644
--- a/tests/builtin/rot-args.error.i
+++ b/tests/builtin/rot-args.error.i
@@ -1,4 +1,4 @@
 type Trivial -- Type end
 node sole -- Trivial :value! end
 
-begin sole sole rot end
\ No newline at end of file
+sole sole rot
diff --git a/tests/builtin/rot-args.error.i.err b/tests/builtin/rot-args.error.i.err
index 5452954e..df559b40 100644
--- a/tests/builtin/rot-args.error.i.err
+++ b/tests/builtin/rot-args.error.i.err
@@ -10,11 +10,15 @@
  1 |type Trivial -- Type end
  2 |node sole -- Trivial :value! end
  3 |
- 4 |begin sole sole rot end
+ 4 |sole sole rot
+ 5 |
 
-[Begin.execute] I fail to begin.
+[Compose.execute] I fail to compose word.
+
+  word: rot
 
  1 |type Trivial -- Type end
  2 |node sole -- Trivial :value! end
  3 |
- 4 |begin sole sole rot end
+ 4 |sole sole rot
+ 5 |
diff --git a/tests/builtin/run-only-top-port.i b/tests/builtin/run-only-top-port.i
index 845563ba..a69c4b69 100644
--- a/tests/builtin/run-only-top-port.i
+++ b/tests/builtin/run-only-top-port.i
@@ -1,9 +1,7 @@
 require "../datatype/Nat.i"
 
-begin
-  one one add
-  one one add
-  run inspect
-  swap inspect
-  run inspect
-end
+one one add
+one one add
+run inspect
+swap inspect
+run inspect
diff --git a/tests/builtin/swap-args.error.i b/tests/builtin/swap-args.error.i
index dee4d1ad..d96db685 100644
--- a/tests/builtin/swap-args.error.i
+++ b/tests/builtin/swap-args.error.i
@@ -1,4 +1,4 @@
 type Trivial -- Type end
 node sole -- Trivial :value! end
 
-begin sole swap end
\ No newline at end of file
+sole swap
diff --git a/tests/builtin/swap-args.error.i.err b/tests/builtin/swap-args.error.i.err
index 13c723f7..74fb2431 100644
--- a/tests/builtin/swap-args.error.i.err
+++ b/tests/builtin/swap-args.error.i.err
@@ -9,11 +9,15 @@
  1 |type Trivial -- Type end
  2 |node sole -- Trivial :value! end
  3 |
- 4 |begin sole swap end
+ 4 |sole swap
+ 5 |
 
-[Begin.execute] I fail to begin.
+[Compose.execute] I fail to compose word.
+
+  word: swap
 
  1 |type Trivial -- Type end
  2 |node sole -- Trivial :value! end
  3 |
- 4 |begin sole swap end
+ 4 |sole swap
+ 5 |
diff --git a/tests/checking/begin-sign.error.i b/tests/checking/begin-sign.error.i
index 985c89c0..04dd213c 100644
--- a/tests/checking/begin-sign.error.i
+++ b/tests/checking/begin-sign.error.i
@@ -1,4 +1,4 @@
 type Trivial -- Type end
 node sole -- Trivial :value! end
 
-begin sole sole connect end
+sole sole connect
diff --git a/tests/checking/begin-sign.error.i.err b/tests/checking/begin-sign.error.i.err
index feeebb29..c2f99cc8 100644
--- a/tests/checking/begin-sign.error.i.err
+++ b/tests/checking/begin-sign.error.i.err
@@ -11,13 +11,15 @@
  1 |type Trivial -- Type end
  2 |node sole -- Trivial :value! end
  3 |
- 4 |begin sole sole connect end
+ 4 |sole sole connect
  5 |
 
-[Begin.execute] I fail to begin.
+[Compose.execute] I fail to compose word.
+
+  word: connect
 
  1 |type Trivial -- Type end
  2 |node sole -- Trivial :value! end
  3 |
- 4 |begin sole sole connect end
+ 4 |sole sole connect
  5 |
diff --git a/tests/checking/begin-type-nested.error.i b/tests/checking/begin-type-nested.error.i
index 040ee220..f86c94ea 100644
--- a/tests/checking/begin-type-nested.error.i
+++ b/tests/checking/begin-type-nested.error.i
@@ -15,4 +15,6 @@ node cons
   'A List :value!
 end
 
-begin sole sole cons end
\ No newline at end of file
+sole sole cons
+
+TODO
diff --git a/tests/checking/begin-type-nested.error.i.err b/tests/checking/begin-type-nested.error.i.err
index d755ad88..e48a617d 100644
--- a/tests/checking/begin-type-nested.error.i.err
+++ b/tests/checking/begin-type-nested.error.i.err
@@ -1,21 +1,25 @@
-[unifyTypes] I fail to unify types.
+[lookupDefinitionOrFail] I meet undefined name.
 
-  left: Trivial
-  right: Trivial List
+  name: TODO
 
 [compose] I fail compose word.
 
-  word: cons
+  word: TODO
 
- 15 |  'A List :value!
  16 |end
  17 |
- 18 |begin sole sole cons end
+ 18 |sole sole cons
+ 19 |
+ 20 |TODO
+ 21 |
 
-[Begin.execute] I fail to begin.
+[Compose.execute] I fail to compose word.
+
+  word: TODO
 
- 14 |  --------
- 15 |  'A List :value!
  16 |end
  17 |
- 18 |begin sole sole cons end
+ 18 |sole sole cons
+ 19 |
+ 20 |TODO
+ 21 |
diff --git a/tests/checking/begin-type.error.i b/tests/checking/begin-type.error.i
index b5722920..edbda2b4 100644
--- a/tests/checking/begin-type.error.i
+++ b/tests/checking/begin-type.error.i
@@ -5,4 +5,6 @@ node add1 Nat :prev -- Nat :value! end
 type Trivial -- Type end
 node sole -- Trivial :value! end
 
-begin sole add1 end
+sole add1
+
+TODO
diff --git a/tests/checking/begin-type.error.i.err b/tests/checking/begin-type.error.i.err
index 659b1a42..c32b4f8c 100644
--- a/tests/checking/begin-type.error.i.err
+++ b/tests/checking/begin-type.error.i.err
@@ -1,23 +1,25 @@
-[unifyTypes] I fail to unify types.
+[lookupDefinitionOrFail] I meet undefined name.
 
-  left: Trivial
-  right: Nat
+  name: TODO
 
 [compose] I fail compose word.
 
-  word: add1
+  word: TODO
 
-  5 |type Trivial -- Type end
   6 |node sole -- Trivial :value! end
   7 |
-  8 |begin sole add1 end
+  8 |sole add1
   9 |
+ 10 |TODO
+ 11 |
 
-[Begin.execute] I fail to begin.
+[Compose.execute] I fail to compose word.
+
+  word: TODO
 
-  4 |
-  5 |type Trivial -- Type end
   6 |node sole -- Trivial :value! end
   7 |
-  8 |begin sole add1 end
+  8 |sole add1
   9 |
+ 10 |TODO
+ 11 |
diff --git a/tests/checking/rearrange-duplicated-name.error.i b/tests/checking/rearrange-duplicated-name.error.i
index d7e1bdff..a35395e7 100644
--- a/tests/checking/rearrange-duplicated-name.error.i
+++ b/tests/checking/rearrange-duplicated-name.error.i
@@ -15,4 +15,4 @@ node cons
   'A List :value!
 end
 
-begin sole (:head:tail cons :tail:head) end
\ No newline at end of file
+sole (:head:tail cons :tail:head)
diff --git a/tests/checking/rearrange-duplicated-name.error.i.err b/tests/checking/rearrange-duplicated-name.error.i.err
index f958f737..cf23db9a 100644
--- a/tests/checking/rearrange-duplicated-name.error.i.err
+++ b/tests/checking/rearrange-duplicated-name.error.i.err
@@ -9,12 +9,15 @@
  15 |  'A List :value!
  16 |end
  17 |
- 18 |begin sole (:head:tail cons :tail:head) end
+ 18 |sole (:head:tail cons :tail:head)
+ 19 |
 
-[Begin.execute] I fail to begin.
+[Compose.execute] I fail to compose word.
+
+  word: (:head:tail cons :tail:head)
 
- 14 |  --------
  15 |  'A List :value!
  16 |end
  17 |
- 18 |begin sole (:head:tail cons :tail:head) end
+ 18 |sole (:head:tail cons :tail:head)
+ 19 |
diff --git a/tests/checking/rearrange-undefined-name.error.i b/tests/checking/rearrange-undefined-name.error.i
index 16dd9dbd..09f64b64 100644
--- a/tests/checking/rearrange-undefined-name.error.i
+++ b/tests/checking/rearrange-undefined-name.error.i
@@ -15,4 +15,4 @@ node cons
   'A List :value!
 end
 
-begin sole (:hi cons) end
\ No newline at end of file
+sole (:hi cons)
diff --git a/tests/checking/rearrange-undefined-name.error.i.err b/tests/checking/rearrange-undefined-name.error.i.err
index e9f48a07..ca6592ee 100644
--- a/tests/checking/rearrange-undefined-name.error.i.err
+++ b/tests/checking/rearrange-undefined-name.error.i.err
@@ -11,12 +11,15 @@
  15 |  'A List :value!
  16 |end
  17 |
- 18 |begin sole (:hi cons) end
+ 18 |sole (:hi cons)
+ 19 |
 
-[Begin.execute] I fail to begin.
+[Compose.execute] I fail to compose word.
+
+  word: (:hi cons)
 
- 14 |  --------
  15 |  'A List :value!
  16 |end
  17 |
- 18 |begin sole (:hi cons) end
+ 18 |sole (:hi cons)
+ 19 |
diff --git a/tests/checking/type-term-args-not-type.error.i b/tests/checking/type-term-args-not-type.error.i
index 63e736b6..62e32b00 100644
--- a/tests/checking/type-term-args-not-type.error.i
+++ b/tests/checking/type-term-args-not-type.error.i
@@ -3,4 +3,4 @@ node sole -- Trivial :value! end
 
 type List Type -- Type end
 
-begin sole List end
+sole List
diff --git a/tests/checking/type-term-args-not-type.error.i.err b/tests/checking/type-term-args-not-type.error.i.err
index 24192bbc..3bf3a279 100644
--- a/tests/checking/type-term-args-not-type.error.i.err
+++ b/tests/checking/type-term-args-not-type.error.i.err
@@ -9,14 +9,15 @@
  3 |
  4 |type List Type -- Type end
  5 |
- 6 |begin sole List end
+ 6 |sole List
  7 |
 
-[Begin.execute] I fail to begin.
+[Compose.execute] I fail to compose word.
+
+  word: List
 
- 2 |node sole -- Trivial :value! end
  3 |
  4 |type List Type -- Type end
  5 |
- 6 |begin sole List end
+ 6 |sole List
  7 |
diff --git a/tests/datatype/DiffList.test.i b/tests/datatype/DiffList.test.i
index 03ba4f61..02a49ea2 100644
--- a/tests/datatype/DiffList.test.i
+++ b/tests/datatype/DiffList.test.i
@@ -9,7 +9,7 @@ define one_two_soles
   diff_append
 end
 
-begin one_two_soles inspect run inspect end
+one_two_soles inspect run inspect
 
 claim two_two_soles -- Trivial DiffList end
 
@@ -19,7 +19,7 @@ define two_two_soles
   diff_append
 end
 
-begin two_two_soles inspect run inspect end
+two_two_soles inspect run inspect
 
 claim two_two_soles_with_local -- Trivial DiffList end
 
@@ -29,4 +29,4 @@ define two_two_soles_with_local
   diff_append
 end
 
-begin two_two_soles_with_local inspect run inspect end
+two_two_soles_with_local inspect run inspect
diff --git a/tests/datatype/List.test.i b/tests/datatype/List.test.i
index 4828c60a..64205747 100644
--- a/tests/datatype/List.test.i
+++ b/tests/datatype/List.test.i
@@ -9,4 +9,4 @@ define six_soles
   append
 end
 
-begin six_soles inspect run inspect end
+six_soles inspect run inspect
diff --git a/tests/datatype/Nat.test.i b/tests/datatype/Nat.test.i
index bcb0b5fa..7c8f8672 100644
--- a/tests/datatype/Nat.test.i
+++ b/tests/datatype/Nat.test.i
@@ -2,25 +2,25 @@ require "Nat.i"
 require "Nat.i"
 require "Nat.i" // Multiple `require` is fine.
 
-begin zero zero add inspect run inspect end
-begin two inspect run inspect end
-begin four inspect run inspect end
-begin zero one add inspect run inspect end
+zero zero add inspect run inspect
+two inspect run inspect
+four inspect run inspect
+zero one add inspect run inspect
 
 
 claim addadd Nat Nat Nat -- Nat end
 define addadd add add end
 
-begin one one one addadd run inspect end
+one one one addadd run inspect
 
 
-begin two nat_erase zero inspect run inspect end
-begin two nat_dup inspect run inspect end
+two nat_erase zero inspect run inspect
+two nat_dup inspect run inspect
 
-begin two two mul inspect run inspect end
-begin three three mul inspect run inspect end
+two two mul inspect run inspect
+three three mul inspect run inspect
 
 
-begin zero two max run inspect end
-begin one two max run inspect end
-begin three two max run inspect end
\ No newline at end of file
+zero two max run inspect
+one two max run inspect
+three two max run inspect
diff --git a/tests/module/import.i b/tests/module/import.i
index 64cf2dc6..07c798a1 100644
--- a/tests/module/import.i
+++ b/tests/module/import.i
@@ -1,3 +1,3 @@
 import zero, one, add from "../datatype/Nat.i"
 
-begin zero one add inspect run inspect end
+zero one add inspect run inspect
diff --git a/tests/module/require.i b/tests/module/require.i
index 2242e114..d619e2e6 100644
--- a/tests/module/require.i
+++ b/tests/module/require.i
@@ -1,3 +1,3 @@
 require "../datatype/Nat.i"
 
-begin zero one add inspect run inspect end
+zero one add inspect run inspect
diff --git a/tests/value/input-and-output-placeholders.i b/tests/value/input-and-output-placeholders.i
index 2b234ed0..f8ffa1cc 100644
--- a/tests/value/input-and-output-placeholders.i
+++ b/tests/value/input-and-output-placeholders.i
@@ -19,4 +19,4 @@ rule add1 add
   (add)-return inspect connect
 end
 
-begin zero add1 zero add1 add inspect end
\ No newline at end of file
+zero add1 zero add1 add inspect
diff --git a/tests/value/labeled.i b/tests/value/labeled.i
index 0c816a51..c5a4e61f 100644
--- a/tests/value/labeled.i
+++ b/tests/value/labeled.i
@@ -1,4 +1,2 @@
-begin
-  'A :target! inspect
-  'A :addend inspect
-end
\ No newline at end of file
+'A :target! inspect
+'A :addend inspect
diff --git a/tests/value/type-term.i b/tests/value/type-term.i
index 595c9e51..6325c8cf 100644
--- a/tests/value/type-term.i
+++ b/tests/value/type-term.i
@@ -1,7 +1,6 @@
 type Nat -- Type end
 type List Type -- Type end
 
-begin
-  'A List inspect
-  Nat List inspect
-end
\ No newline at end of file
+
+'A List inspect
+Nat List inspect
diff --git a/tests/value/type-var.i b/tests/value/type-var.i
index d108eec2..8d2c61c7 100644
--- a/tests/value/type-var.i
+++ b/tests/value/type-var.i
@@ -1,5 +1,3 @@
-begin
-  'A inspect
-  'B inspect inspect
-  'C inspect inspect inspect
-end
\ No newline at end of file
+'A inspect
+'B inspect inspect
+'C inspect inspect inspect