proved kernelc tree height and size examples
added lemma and smt support for proving the find example
proved kernelc tree find example
revised the smt translation of bool2Int
proved mirror example
Merge branch 'unified-builtins2' into prove-kernelc-tree-examples

Conflicts:
	samples/kernelc/kernelc-syntax.k
fixed failing tests
Merge pull request #865 from yilongli/prove-kernelc-tree-examples

Prove kernelc tree examples