Fixed bug: lookup' must use = instead of eq_type to compare types of variables, otherwise pattern matching algorithm may loop.
Fixed bug: lookup' must use = instead of eq_type to compare types of
variables, otherwise pattern matching algorithm may loop.

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle