fixed problem with earlier commit about nominal_function_common; added facility for specifying an invariant - added a definition of frees_set which need a finiteness invariant
quick_and_dirty := true;
no_document use_thys ["Quotient",
"~~/src/HOL/Library/LaTeXsugar",
"~~/src/HOL/Quotient_Examples/FSet" ];
use_thys ["Paper"];