program ::= program identifier [decl-list] begin stmt-list end "."

decl-list ::= decl ";" { decl ";"}

decl ::= ident-list is type

ident-list ::= identifier {"," identifier}

type ::= int | float | char

stmt-list ::= stmt {";" stmt}

stmt ::= assign-stmt | if-stmt | while-stmt | repeat-stmt | read-stmt | write-stmt

assign-stmt ::= identifier "=" simple_expr

if-stmt ::= if condition then stmt-list end | if condition then stmt-list else stmt-list end

condition ::= expression

repeat-stmt ::= repeat stmt-list stmt-suffix

stmt-suffix ::= until condition

while-stmt ::= stmt-prefix stmt-list end

stmt-prefix ::= while condition do

read-stmt ::= read "(" identifier ")"

write-stmt ::= write "(" writable ")"

writable ::= simple-expr | literal

expression ::= simple-expr | simple-expr relop simple-expr

simple-expr ::= term | simple-expr addop term

term ::= factor-a | term mulop factor-a

fator-a ::= factor | "!" factor | "-" factor

factor ::= identifier | constant | "(" expression ")"

relop ::= "==" | ">" | ">=" | "<" | "<=" | "!="

addop ::= "+" | "-" | "||"

mulop ::= "*" | "/" | "&&"

constant ::= integer_const | float_const | char_const

digit ::= [0-9]

carac ::= um dos caracteres ASCII

caractere ::= um dos caracteres ASCII, exceto quebra de linha

integer_const ::= digit+

float_const ::= digit+ “.”digit+

char_const ::= " ‘ " carac " ’ "

literal ::= "{" caractere* "}"

identifier ::= letter (letter | digit | " _")*

letter ::= [A-Za-z]