unifyTheta theta1 theta2
= do { checkTc (equalLength theta1 theta2)
(vcat [ptext (sLit "Contexts differ in length"),
- nest 2 $ parens $ ptext (sLit "Use -fglasgow-exts to allow this")])
+ nest 2 $ parens $ ptext (sLit "Use -XRelaxedPolyRec to allow this")])
; uList unifyPred theta1 theta2
}