remove overloading of "max_facts" -- it already controls the number of facts passed to ATPs for 'learn_prover'

merged

tuned exercises

use Code.abort instead of undefined in auto-generated equations

have MaSh minimize

tweaked signature

strengthened tactic to deal with 'False ==> ...'

made theorem extraction code not delve too far when looking at local fact, by relying on 'strip_thm' instead of (wrongly) reverse-engineering proof terms

improved duplicate detection in "build_name_tables" by ensuring that the earliest occurrence of a duplicate (if it exists) gets picked as the canonical instance

updated S/H docs