Function lemma_parser_congruent_apply 

pub broadcast proof fn lemma_parser_congruent_apply<A, B>(a: A, b: B, input: Seq<u8>)
where
    A: SpecParser,
    B: SpecParser<PVal = A::PVal>,

requires

parser_congruent(a, b),

ensures

#[trigger] a.spec_parse(input) == #[trigger] b.spec_parse(input),