---------------------------------------------------------------------- DIV_CONV (reduceLib) ---------------------------------------------------------------------- DIV_CONV : conv SYNOPSIS Calculates by inference the result of dividing, with truncation, one numeral by another. LIBRARY reduce DESCRIBE If {m} and {n} are numerals (e.g. {0}, {1}, {2}, {3},...), then {DIV_CONV ``m DIV n``} returns the theorem: |- m DIV n = s where {s} is the numeral that denotes the result of dividing the natural number denoted by {m} by the natural number denoted by {n}, with truncation. FAILURE {DIV_CONV tm} fails unless {tm} is of the form {``m DIV n``}, where {m} and {n} are numerals, or if {n} denotes zero. EXAMPLE > DIV_CONV ``0 DIV 0``; Exception- HOL_ERR {message = "attempt to divide by zero", origin_function = "DIV_CONV", origin_structure = "Arithconv"} raised > DIV_CONV ``x DIV 12``; Exception- ... > DIV_CONV ``0 DIV 12``; val it = |- 0 DIV 12 = 0 : thm > DIV_CONV ``7 DIV 2``; val it = |- 7 DIV 2 = 3 : thm ----------------------------------------------------------------------