X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/c144ab4f7d780f14f8f5c83c72b17a7c54c01150..5a19b5dfdde3f31feef4443442cc1c5c0bad6484:/math/ec-bin.c

diff --git a/math/ec-bin.c b/math/ec-bin.c
index d91b0343..c7fe96d4 100644
--- a/math/ec-bin.c
+++ b/math/ec-bin.c
@@ -73,6 +73,7 @@ static ec *ecfind(ec_curve *c, ec *d, mp *x)
       v = F_MUL(f, v, u, y);	    /* %$B = A x^{-2} = x + a + b x^{-2}$% */
       y = F_QUADSOLVE(f, y, v);		/* %$z^2 + z = B$% */
       if (y) y = F_MUL(f, y, y, x);	/* %$y = z x$% */
+      /* Hence %$y^2 + x y = (z^2 + z) x^2 = A$% */
     }
     MP_DROP(u);
     MP_DROP(v);