source 2007 Bernstein--Lange
parameter ccd
assume ccd = c*c*d
compute XX = X1^2
compute YY = Y1^2
compute ZZ = Z1^2
compute D = XX+YY
compute DD = D^2
compute E = 4 (D-ccd ZZ)
compute H = 2 D (YY-XX)
compute P = DD-XX E
compute Q = DD-YY E
compute QQ = Q^2
compute X3 = (H+Q) ((Q+X1)^2-QQ-XX)
compute Y3 = 2 (H-P) P Y1
compute Z3 = P ((Q+Z1)^2-QQ-ZZ)
