first stage in tidying up Real and Hyperreal.
Factor cancellation simprocs
inverse #0 = #0
simprules for division
corrected ambigous syntax definitions in Hyperreal
consts last :: 'a list => 'a
recdef last "measure (%xs. length xs)"
"last [x] = x"
"last (x#y#zs) = last (y#zs)"