Revert "cvc3 understand definition"
- When the encoding can't encode a definition it transform it into an axiom. But it's not the same than before. The differences is that eliminate algebraic is before this transformation into axiom and not after. So if the definition start with a match, in one case that give different nice axioms, and in the other case that introduce a match function which is polymorph and not well used by provers. Possible solutions : 1) make the match function easier to use with some modification to its definition and discriminate it. 2) Eliminate the match function when the encoding tranform a definition into axioms. This reverts commit 1f652980.