(primitive) expand the current function call without simplification
Examples: expand -- expand and do not simplify.
For example, if the current subterm is
regardless of the top-level hypotheses and the governors.
General Form: (expand &optional do-not-expand-lambda-flg)
Expand the function call at the current subterm, and do not simplify. The options have the following meanings:
do-not-expand-lambda-flg: default is nil; otherwise, the result should be a lambda expression