honor "metisFT" in Mirabelle

make "full_types" take precedence over "type_sys"

crank up Metis's timeout for SMT solvers, since users love Metis

generate a "using [[smt_solver = ...]]" command if a proof is found by another SMT solver than the current one, to ensure it's also used for reconstruction

make sure first-order occurrences of "False" and "True" are handled correctly -- this broke when adding proper support for higher-order occurrences

consider "finite" overloaded in "precise_overloaded_args" mode

added timeout max for remote server invocation

fix translation of higher-order equality ("fequal") if "precise_overloaded_args" is "true"

fix Vampire parsing problem

improve partially tagged encoding by adding a helper fact that coalesces consecutive "ti" tags

example tuning

remove at most one double negation -- any other double negations are part of some higher-order reasoning and should be left alone, cf. "HO_Reas.thy"

weaken the "expect" flag so that it doesn't trigger errors if a prover is not installed

added example to exercise higher-order reasoning with Sledgehammer and Metis

added Sledgehammer support for higher-order propositional reasoning

add Metis support for higher-order propositional reasoning

implemented partially-typed "tags" type encoding

implemented "no_types" encoding, which is too unsound to be useful but can come in handy for evaluations

implemented new type system encoding "overload_args", which is more lightweight than "const_args" (the unsound default) and hopefully almost as sound

tuning: unused var

added "type_sys" option to Sledgehammer

merged

updated SMT certificates

fixed proof reconstruction for lambda-lifted problems (which broke when the lambda-lifting code was changed to operate on terms instead of on theorems)

adapted the Z3 proof parser to recent changes in Z3's proof format; keep the proof steps in an ordered list instead of in an Inttab (simplifies proof reconstruction code)

also show function definitions for higher-order free variables in Z3 models

always add pair rules and function update rules automatically (Boogie provides pairs and function update as built-in concepts and does not generate background axioms for them)

re-implemented eta-expansion, lambda-lifting, and explicit application on terms (exploiting the control over the term structure); abolished SMT interface concept in favor of solver classes (now also the translation configuration is stored in the context); proof reconstruction is now expected to return a theorem stating False (and hence needs to discharge all hypothetical definitions); built-in functions carry additionally their arity and their most general type; slightly generalized the definition of fun_app

re-ordered SMT normalization code (eta-normalization, lambda abstractions and partial functions will be dealt with on the term level); added simple trigger inference mechanism; added syntactic checks for triggers and quantifier weights; factored out the normalization of special quantifiers (used to be in the eta-normalization part); normalization now unfolds abs/min/max (not SMT-LIB-specific); rules for pairs and function update are not anymore added automatically to the problem; more aggressive rewriting of natural number operations into integer operations (minimizes the number of remaining nat-int coercions); normalizations are now managed in a class-based manner (similar to built-in symbols)

added option to enable trigger inference; better documentation of triggers and SMT available options