fn logical_negation(state : &mut State) {
    let mut negation = 0;
    if state.stack.pop() == 0 {
        negation = 1;
    }
    state.stack.push(negation);
}
// logical_negation tests if the top most value is 0
logical_negation tests if the top most value is 0
logical_negation tests if the top most value is 0
fn logical_negation(state : &mut State) {
    let mut negation = 0;
    if state.stack.pop() == 0 {
        negation = 1;
    }
    state.stack.push(negation);
}
fn logical_negation ( state : & mut State ) { let mut negation = 0 ; if state . stack . pop ( ) == 0 { negation = 1 ; } state . stack . push ( negation ) ; }
logical_negation tests if the top most value is 0
logical_negation tests if the top most value is 0
state
&mut State
state
&mut State