Module = MODULE ident ";" [ImportList] DeclSeq [BEGIN StatementSeq] END ident ".". ImportList = IMPORT [ident ":="] ident {"," [ident ":="] ident} ";". DeclSeq = { CONST {ConstDecl ";" } | TYPE {TypeDecl ";"} | VAR {VarDecl ";"}} {ProcDecl ";" | ForwardDecl ";"}. ConstDecl = IdentDef "=" ConstExpr. TypeDecl = IdentDef "=" Type. VarDecl = IdentList ":" Type. ProcDecl = PROCEDURE [Receiver] IdentDef [FormalPars] ";" DeclSeq [BEGIN StatementSeq] END ident. ForwardDecl = PROCEDURE "^" [Receiver] IdentDef [FormalPars]. FormalPars = "(" [FPSection {";" FPSection}] ")" [":" Qualident]. FPSection = [VAR] ident {"," ident} ":" Type. Receiver = "(" [VAR] ident ":" ident ")". Type = Qualident | ARRAY [ConstExpr {"," ConstExpr}] OF Type | RECORD ["("Qualident")"] FieldList {";" FieldList} END | POINTER TO Type | PROCEDURE [FormalPars] FieldList = [IdentList ":" Type]. StatementSeq= Statement {";" Statement}. Statement = [Designator ":=" Expr | Designator ["(" [ExprList] ")"] | IF Expr THEN StatementSeq {ELSIF Expr THEN StatementSeq} [ELSE StatementSeq] END | CASE Expr OF Case {"|" Case} [ELSE StatementSeq] END | WHILE Expr DO StatementSeq END | REPEAT StatementSeq UNTIL Expr | FOR ident ":=" Expr TO Expr [BY ConstExpr] DO StatementSeq END | LOOP StatementSeq END | WITH Guard DO StatementSeq {"|" Guard DO StatementSeq} [ELSE StatementSeq] END | EXIT | RETURN [Expr]]. Case = [CaseLabels {"," CaseLabels} ":" StatementSeq]. CaseLabels = ConstExpr [".." ConstExpr]. Guard = Qualident ":" Qualident. ConstExpr = Expr. Expr = SimpleExpr [Relation SimpleExpr]. SimpleExpr = ["+" | "-"] Term {AddOp Term}. Term = Factor {MulOp Factor}. Factor = Designator ["(" [ExprList] ")"] | number | character | string | NIL | Set | "(" Expr ")" | " ~ " Factor. Set = "{" [Element {"," Element}] "}". Element = Expr [".." Expr]. Relation = "=" | "#" | "<" | "<=" | ">" | ">=" | IN | IS. AddOp = "+" | "-" | OR. MulOp = " * " | "/" | DIV | MOD | "&". Designator = Qualident {"." ident | "[" ExprList "]" | "^" | "(" Qualident ")"}. ExprList = Expr {"," Expr}. IdentList = IdentDef {"," IdentDef}. Qualident = [ident "."] ident. IdentDef = ident [" * " | "-"].