//define a lexical analyser called Exercice6

grammar Exercice6;

full_expr: expr ';' EOF ;

expr:
    | LBRA expr RBRA expr
    | LPAR expr RPAR expr
    | 
    ;

LPAR: '(' ;
RPAR: ')' ;
LBRA: '[' ;
RBRA: ']' ;
CHARS: ~[()[\]] -> skip;
WS: [ \t\r\n]+ -> skip ; // skip spaces, tabs, newlines