numeric-expression (+ | plus) numeric-expression

This is OmniMark's addition operator. Either the keyword plus or the punctuational operator + can be used, though + is the preferred form.

Usage example:

  43 + 967
  12 + 19 + -35
  a + b + c + d    ;each letter being a counter variable
  a plus b plus c plus d   ;each letter being a counter variable