SubtractEvaluateOperator  273 Magick++/lib/Magick++/Include.h   using MagickCore::SubtractEvaluateOperator;
SubtractEvaluateOperator  938 magick/option.c     { "Subtract", (ssize_t) SubtractEvaluateOperator, MagickFalse },
SubtractEvaluateOperator  369 magick/statistic.c     case SubtractEvaluateOperator: