### Input
let Bool = (T: Type) -> T -> T -> T;
let true = (T: Type) => (v1: T) => (v2: T) => v1;
let false = (T: Type) => (v1: T) => (v2: T) => v2;

grammar {
    adapt rule expr {
        group or {
            e1 Bool true e2 <- e1:#this "||" e2:#next;
        }
        group and {
            e1 Bool e2 false <- e1:#this "&&" e2:#next;
        }
        adapt group base {
            b _ e1 e2 <- "if" b:expr "{" e1:expr "}" "else" "{" e2:expr "}";
            b Bool false true <- "!" b:#this;
        }
    }
    adapt rule keyword {
        "if";
    }

}

let x = false;
if true && x || !false {
    true
} else {
    false
}

### Eval
(T: Type) => (v1: T) => (v2: T) => v1

### Type
(T: Type) -> T -> T -> T