[maxmsp] Object to get the difference in changing signal

Here's one that utilizes lazy-evaluation:

#P window setfont "Sans Serif" 9.;
#P flonum 30 228 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P flonum 29 154 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P window linecount 1;
#P newex 29 176 27 196617 t f f;
#P newex 30 203 27 196617 - 0.;
#P connect 0 0 3 0;
#P connect 2 0 1 0;
#P connect 1 1 0 0;
#P connect 1 0 0 1;
#P window clipboard copycount 4;