inline curve_divisor_bilinear_map

jacobian/divisor.c

@@ -110,23 +110,6 @@ curve_divisor_section_as_matrix(GEN X, GEN s, GEN C1, GEN piv2, GEN R2) {
   return gerepileupto(av, M);
 }
 
-/*
-  Given an effective divisor  D  on  X, three subspaces
-  V_1, V_2, V_3  of space of the form  \Gamma(X,{\cal L}^i)
-  such that  V_3  is the product of  V_1 and V_2,  return
-  the induced map on quotient spaces.
-*/
-static GEN
-curve_divisor_bilinear_map(GEN X, GEN C1, GEN C2, GEN piv3, GEN R3) {
-  long i, n = lg(C1) - 1;
-  pari_sp av = avma;
-  GEN mu = cgetg(n + 1, t_VEC);
-  for (i = 1; i <= n; i++)
-    gel(mu, i) = curve_divisor_section_as_matrix(X, gel(C1, i),
-						 C2, piv3, R3);
-  return gerepileupto(av, mu);
-}
-
 /*
   Given a curve  X  and a divisor  D  represented as the
   _two_ subspaces  W_D = \Gamma(X,{\cal L}^d(-D))  and
@@ -153,10 +136,10 @@ curve_divisor_algebra (GEN X, GEN W_D, GEN W_2_D,
   GEN C;
   GEN algebra, basis;
   int try_monogenic = 1;  /* TODO: useful criterion */
+  long deg_D = lg(V) - lg(W_D), i;
 
   if (try_monogenic) {
     GEN s, t, M, N, A = NULL, v;
-    long deg_D = lg(V) - lg(W_D), i;
     int done = 0;
     while (!done) {
       if (A == NULL) {
@@ -187,7 +170,10 @@ curve_divisor_algebra (GEN X, GEN W_D, GEN W_2_D,
   } else {
     GEN mu, algebra_basis;
     C = matsmall_complement(V, W_D, p, T);
-    mu = curve_divisor_bilinear_map(X, C, C, piv2, R_2);
+    mu = cgetg(deg_D + 1, t_VEC);
+    for (i = 1; i <= deg_D; i++)
+      gel(mu, i) = curve_divisor_section_as_matrix(X, gel(C, i),
+						   C, piv2, R_2);
     /*
       Compute the algebra  \Gamma(D,\O_D)  and its action
       on  \Gamma(D,i^*{\cal L}).