To-Do
 1. Fractions
+2. Tests
 3. expression as unit's val
+4. Revisar reduce y pasar a map
+5. mk :m recurse down primero
 6. Going multiprocess
 7. Functions! Derivate! Integrate!


import Exun.Pattern
import Exun
import Exun.

umatch "f(g(x))*g'x","cos(sin(x))*cos(x)"
umatch "u*v'x","x*cos(x)"
umatch("u*v'x","x")
umatch("g(y)+f'x","1+x+y")
umatch("f(x)","sin(x)")
umatch("f(2*x)","sin(2*x)")