register pmf as BNF
add lemma
add lemma following a proof suggestion by Joachim Breitner
removed some add-ons from modules that are relevant for the inference kernel;
tuned;
named_theorems: multiple args;
more careful ML source positions, for improved PIDE markup;
misc tuning and modernization;
misc tuning and modernization;
tuned;
tuned signature;
update CVC4 version docs
renamed 'veriT' to 'verit', to stick to all-lowercase rule for prover names
one more CVC4 option that helps
added Z3 reconstruction rule suggested by F. Maric
no need for subset operation as a primitive in Nitpick, esp. that its implementation was unsound (cf. Rene Thiemann's 16 Oct 2014 email on isabelle mailing list)
updated NEWS
improved message in 'co' case
careful with de Bruijn indices
smoothly handle unit codatatypes in 'primcorec'