reactivated Scala check

corrected range check once more

added Code_Natural.thy

reactivated Scala check; tuned import order

reactivated Scala check

modified namespace policy

use Natural as index type for Haskell and Scala

merged

keep track of clause numbers for SPASS now that we generate FOF rather than CNF problems; this is rather involved because the Flotter FOF-to-CNF translator is normally implicit. We must make this an explicit step and parse the Flotter output to find out which clauses correspond to which formulas.

first step in using "fof" rather than "cnf" in TPTP problems