Computes by inference the result of applying a predicate to elements of a list.
DESCRIPTION
ALL_EL_CONV takes a conversion conv and a term tm in the following form:
ALL_EL P [x0;...xn]
It returns the theorem
|- ALL_EL P [x0;...xn] = T
if for every xi occurring in the list, conv (--`P xi`--) returns a
theorem |- P xi = T, otherwise, if for at least one xi, evaluating
conv (--`P xi`--) returns the theorem |- P xi = F, then it returns
the theorem
|- ALL_EL P [x0;...xn] = F
FAILURE
ALL_EL_CONV conv tm fails if tm is not of the form described above, or
failure occurs when evaluating conv (--`P xi`--) for some xi.