func divBy x 0 = x / yield 'INF
func divBy x "y" = x / yield 'NAN
func divBy x y = x / y

proc main!() {
    let x = with divBy 3 0 {
        when 'NAN cancel 0
        when 'INF resume 1
        else yield
    }

    let y = with divBy 4 "y" {
        when 'NAN cancel 9
        when 'INF resume 2
        else yield
    }

    let z = with divBy 4 2 {
        when 'NAN cancel 9
        when 'INF resume 4
        else yield
    }

    exit x + y + z
}