+=== Word: /MOD
+
+....
+Data stack: ( v1 v2 -- q r )
+....
+
+"/MOD" (div-mod) is a function word that replaces a pair of values
+with the results of signed integer division of the first, v1, divided
+by the second, v2. To that end, the values are 64-bit signed integers.
+The result is the integer quotient, q, and the remainder, r, where q
+and r are the respectively largest and smallest integers to satisfy
+the formula:
+....
+ v1 = q * v2 + r
+....