2011-05-14 ago modernized functor names;
2011-03-26 ago more direct loose_bvar1;
2010-07-08 ago tuned titles
2010-05-05 ago farewell to old-style mem infixes -- type inference in situations with mem_int and mem_string should provide enough information to resolve the type of (op =)
2010-03-13 ago removed old CVS Ids;
2009-08-29 ago eliminated hard tabs;
2008-05-07 ago Replaced Pattern.eta_contract_atom by Envir.eta_contract.
1997-07-22 ago Removal of the tactical STATE
1997-03-05 ago Now uses eta_contract_atom for greater speed
1996-01-29 ago expanded tabs
1995-04-07 ago Local version of (original) hypsubst: needs no simplifier