<> (eq ?x ?x) (#t)
<> (eq ?x ?y) (#f)
<> (q ?x) (q ?x)
<> (if ?c ?t ?f) (if/q ?c q ?t q ?f)
<> (if/q (#t) q ?t q ?f) (?t)
<> (if/q (#f) q ?t q ?f) (?f)
if (eq foo bar) (if (eq foo baz) a b) (if (eq foo foo) b c)