Factor : @{
    Int                 # built-in 64-bit signed integer token
    '(' Expr ')'
}

Term : @{
    Term '*' Factor     $1 * $3
    Term '/' Factor     $1 / $3
    Factor
}

Expr : @{
    Expr '+' Term       $1 + $3
    Expr '-' Term       $1 - $3
    Term
}

Expr