never {
s0_init:
    if
    :: !(q) -> goto accept_s2
    :: (q) -> goto s3
    :: !(p) -> goto accept_s4
    :: (1) -> goto s1
    fi;
s1:
    if
    :: !(p) -> goto accept_s4
    :: (1) -> goto s1
    fi;
s3:
    if
    :: !(q) -> goto accept_s2
    :: (q) -> goto s3
    fi;
accept_s2:
    if
    :: !(q) -> goto accept_s2
    :: (q) -> goto s3
    fi;
accept_s4:
    if
    :: !(p) -> goto accept_s4
    fi;
}