generalize LIMSEQ_vector to tendsto_vector

generalize orthogonal_clauses

remove redundant lemma vector_dist_norm

remove redundant lemma norm_0

generalize some euclidean space lemmas

prove lemma openin_subopen without using choice

move path-related stuff into new theory file

add new Multivariate_Analysis files to IsaMakefile

move operator norm stuff to new theory file

eliminated spurious sledgehammer invocation;

merged

merged

merged

enclose case expression in brackets

catch the right exception

eliminate trivial case splits from Isar proofs

remove debugging code

merged

minor improvements

identify axioms/conjectures more reliably in ATP proofs (an empty dependency list doesn't always indicate an axiom or conjecture!)

added "no_atp" for theorems that are automatically used or included by Sledgehammer when appropriate (about combinators and fequal)

in "overlord" mode: ignore problem prefix specified in the .thy file

uncomment code

redid some Sledgehammer/Metis proofs

fix more "undeclared symbol" errors related to SPASS's DFG format

be more discriminate: some one-line Isar proofs are silly

one-step Isar proofs are not always pointless

the SPASS output syntax is more general than I thought -- such a pity that there's no documentation

redo more Metis/Sledgehammer example

fixed definition of "bad frees" so that it actually works