never {
s0_init:
    if
    :: !(p) -> goto s0_init
    :: (p) -> goto s1
    fi;
s1:
    if
    :: !(q) -> goto s1
    :: (q) -> goto s2
    fi;
s2:
    if
    :: !(r) -> goto s2
    :: (r) -> goto s3
    fi;
s3:
    if
    :: !(s) -> goto s3
    :: (s) -> goto accept_s4
    fi;
accept_s4:
    if
    :: (1) -> goto s0_init
    fi;
}