Hipspec performs worse if there are missing type signatures

[sergei-grechanik]

For example, hipspec cannot prove the prop from here unless the type signature for (++) is uncommented.

Judging by the *.mlw files, this is due to redundant apps. The bug seems to be introduced by the commit a63a8fe

[danr]

Thanks sergei-grechanik, I have had a similar problem before, yours differs by involving a polymorphic function. The culprit is simpFun in SimplifyRich, but I will have to tend to it later.