notin.test

<<< native
[ EIdentifier "x"
, ESymbol Rel "\8712"
, EIdentifier "y"
, ESymbol Bin "\8743"
, EIdentifier "x"
, ESymbol Rel "\8713"
, EIdentifier "y"
]
>>> eqn
x \[u2208] y \[u2227] x \[u2209] y