Reason: vector in in init folder was introducing an overload (`::`) for
all Lean users. The workaround (use `local infix ::`) was
counterintuitive.
We currently have no special support for bitvectors in the code
generator. Thus, there is no need to have vector and bitvec in the init
folder right now. Moreover, the new parser and elaborator (issue #1674) should
provide better ways of managing overloaded symbols.
@joehendrix This commit is implementing the matcher that postpones
implicit arguments. The lemma get_data_mk_byte can be proved without
using any hacks in the type_context unifier.
I also added the trace class: simplify.implicit_failure
If we use the command
set_option trace.simplify.implicit_failure true
Then, the simplifier will generate a diagnostic message every time it
succeeds in the explicit part, but fails in the implicit one.
Please feel free to suggest a better name to his option.
BTW, we can now easily extend the matcher with additional features.
I'm wondering if we will eventually want to write some of these
extensions in Lean.
