Conversion to prove whether one integer literal of type :int is <
The call INT_LT_CONV `c1 < c2` where c1 and c2 are integer
literals of type :int, returns whichever of |- c1 < c2 <=> T or
|- c1 < c2 <=> F is true. By an integer literal we mean either &n or
-- &n where n is a numeral.
Fails if applied to a term that is not the appropriate inequality comparison on
two permitted integer literals of type :int.
# INT_LT_CONV `-- &18 < &64`;;
val it : thm = |- -- &18 < &64 <=> T
The related function REAL_RAT_LT_CONV subsumes this functionality, also
applying to rational literals. Unless the restriction to integers is desired or
a tiny efficiency difference matters, it should be used in preference.