This allows users to now use to apply a tactic in all hypotheses as well as the goal, we add support for all
interactive tactics using location: rewrite, simp, dsimp, unfold, and delta including each tactics many variants.
They can be used to store user state in the tactic_state object.
@Armael @jroesch: The new file tests/lean/run/tactic_ref.lean contains a few examples.
closes#1634
This commit also changes the semantic of `tactic.focus [tac_1, ..., tac_n]`.
It now fails if the number of goals is not `n`.
Before it would only fail if there were more tactics than goals.
@Armael: See tests/lean/run/handthen.lean for examples of the new notation.
This commit fixes issue #1631. However, it is not a perfect solution.
This commit improves the predicate that checks whether a definition is
noncomputable or not. This predicate was implemented before we had
a code generator.
We should refactor the code and use the code generator to check
whether a definition is noncomputable or not. Otherwise, we will
keep finding mismatches between the predicate at noncomputable.cpp
and what the code generator implements.
@Armael: this commit implements the `introv` tactic.
The implementation uses an auxiliary `intros_dep` that introduces new
hypotheses with forward dependencies.
The `tactic.introv` tactic implemented at library/init/meta/tactic.lean
is the main implementation, but it is not nice for interactive use since
users would have to write
```
tactic.introv [`h1, `h2]
```
To make it more conveninent to use, we define another
```
meta def introv (ns : parse ident_*) : tactic unit :=
tactic.introv ns >> return ()
```
This one is in the namespace `tactic.interactive`, and
uses parser extensions. The argument `parse ident_*` instructs
the parser to parse 0 or more identifiers and create a term
of type `list name` containing these identifiers.
rel_tac is a tactic used for synthesizing a well founded relation.
The default implementation just uses type class resolution.
More sophisticated strategies may need to access the set of recursive
equations. This commit addresses this need.
(1) The lhs and rhs will be reduced to whnf before getting the constructor apps
(2) If the lhs and rhs are distinct constructors, it discharges the goal by contradiction
(3) The interactive injection tactic will try to close the goal by assumption if successful
