findifs.lib
LIB "findifs.lib"; " EXAMPLE:"; ==> EXAMPLE: ring r = (0,dt,dh,A),Tt,dp; poly p = (Tt*dt+dh+1)^2+2*A; string s = texpoly("",p); s; ==> $dt^{2}\cdot Tt^{2}+(2dtdh+2dt)\cdot Tt+(dh^{2}+2dh+2A+1)$ string t = xchange(s,"dh","dt"); t; ==> $dh^{2}\cdot Tt^{2}+(2dhdt+2dh)\cdot Tt+(dt^{2}+2dt+2A+1)$