Delete members of SEQ which are `equal' to ELT, and return the result.
SEQ must be a sequence (i.e. a list, a vector, or a string).
The return value is a sequence of the same type.
If SEQ is a list, this behaves like `delq', except that it compares
with `equal' instead of `eq'. In particular, it may remove elements
by altering the list structure.
If SEQ is not a list, deletion is never performed destructively;
instead this function creates and returns a new vector or string.
Write `(setq foo (delete element foo))' to be sure of correctly
changing the value of a sequence `foo'. (fn ELT SEQ)