X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/c973f431a370a3adbcb3c94f76dc6896a7279235..423acb9483f672df5cf220e386b7d85e35b95fb8:/math/mprand.h

diff --git a/math/mprand.h b/math/mprand.h
index 0c193c03..a088df8a 100644
--- a/math/mprand.h
+++ b/math/mprand.h
@@ -58,6 +58,9 @@
  *		uniformly distributed in the interval %$[2^{b - 1}, 2^b)$%.
  *		The result is then ORred with the given @or@ value.  This
  *		will often be 1, to make the result odd.
+ *
+ *		The length @b@ may be zero; but %$\texttt{or} \ge 2^b$% is
+ *		not permitted.
  */
 
 extern mp *mprand(mp */*d*/, unsigned /*b*/, grand */*r*/, mpw /*or*/);
@@ -73,7 +76,7 @@ extern mp *mprand(mp */*d*/, unsigned /*b*/, grand */*r*/, mpw /*or*/);
  *		interval %$[0, l)$%.
  *
  * Use:		Generates a uniformly-distributed pseudorandom number in the
- *		appropriate range.
+ *		appropriate range.  We must have %$l > 0$%.
  */
 
 extern mp *mprand_range(mp */*d*/, mp */*l*/, grand */*r*/, mpw /*or*/);