ROOTS

more precise slicing computation and output when not enough lemmas are available (e.g. with the 'only' syntax 'sledgehammer (lem1 lem2 lem3)')

src/Pure
src/FOL
src/HOL
src/ZF
src/CCL
src/CTT
src/Cube
src/FOLP
src/LCF
src/Sequents
src/Doc
src/Tools