Keep filter input syntax

First step to remove nonstandard "[x <- xs. P]" syntax: only input

--HG--
extra : amend_source : a2e6a2312b63a5ed1947d3302e43341c073c9f03

session-qualified theory imports: isabelle imports -U -i -d '~~/src/Benchmarks' -a;

isabelle update_cartouches -c -t;

improved 'datatype_compat' further for recursion through functions

adapted to 'xxx_{case,rec}' renaming, to new theorem names, and to new variable names in theorems
* * *
more transition of 'xxx_rec' to 'rec_xxx' and same for case
* * *
compile
* * *
'rename_tac's to avoid referring to generated names
* * *
more robust scripts with 'rename_tac'
* * *
'where' -> 'of'
* * *
'where' -> 'of'
* * *
renamed 'xxx_rec' to 'rec_xxx'

standardized symbols via "isabelle update_sub_sup", excluding src/Pure and src/Tools/WWW_Find;

eliminated prems;

modernized specifications;

modernized primrec

tuned proofs and added some lemmas

no base sort in class import

Unified syntax of nominal_primrec with the one used by fun(ction) and new
version of primrec command.

Example for using the generalized version of nominal_inductive.

added new example