never {
s2_init:
    if
    :: !(r) -> goto s2_init
    :: (p) && !(q) && (r) -> goto accept_s1
    :: !(p) && !(q) && (r) -> goto s3
    fi;
s3:
    if
    :: !(p) && !(q) -> goto s3
    :: (p) && !(q) -> goto accept_s1
    fi;
accept_s1:
    if
    :: !(r) -> goto accept_s1
    :: (p) && !(q) -> goto accept_s1
    :: !(p) && !(q) && (r) -> goto s3
    fi;
}