+/* --- @pgen_granfrob@ --- *
+ *
+ * Arguments: @mp *n@ = an integer to test
+ * @int a, b@ = coefficients; if @a@ is zero then choose
+ * automatically
+ *
+ * Returns: One of the @PGEN_...@ codes.
+ *
+ * Use: Performs a quadratic version of Grantham's Frobenius
+ * primality test, which is a simple extension of the standard
+ * Lucas test.
+ *
+ * If %$a^2 - 4 b$% is a perfect square then the test can't
+ * work; this function returns @PGEN_ABORT@ under these
+ * circumstances.
+ *
+ * If @a@ is zero on entry, then the function will choose
+ * suitable parameters deterministically -- i.e., it always
+ * chooses the same parameters for a given %$n$%.
+ */
+
+extern int pgen_granfrob(mp */*n*/, int /*a*/, int /*b*/);
+