01-something-cons.egi

--
-- Match-site dual check, direct supply (paper Appendix B, Case 2).
-- `something : Matcher b` cannot fill the cons pattern's slot
-- MatcherSlot [a'] [Integer]: the structural check b' <: [a'] fails.
--
-- Expected: Type error (Matcher b vs MatcherSlot [a'] [Integer])
--

def t := matchAll [1, 2, 3] as something with $x :: $xs -> (x, xs)