pub fn join_variable_intros(
tup: (VariableIntro, Vec<(Operator, VariableIntro)>),
) -> (Option<Operator>, Vec<VariableIntro>)
pub fn join_variable_intros(
tup: (VariableIntro, Vec<(Operator, VariableIntro)>),
) -> (Option<Operator>, Vec<VariableIntro>)