=head1 NAME
BN_set_bit, BN_clear_bit, BN_is_bit_set, BN_mask_bits, BN_lshift,
-BN_lshift1, BN_rshift, BN_rshift1 - Bit operations on BIGNUMs
+BN_lshift1, BN_rshift, BN_rshift1 - bit operations on BIGNUMs
=head1 SYNOPSIS
B<r> (C<r=a/2^n>). BN_rshift1() shifts B<a> right by one and places
the result in B<r> (C<r=a/2>).
+For the shift functions, B<r> and B<a> may be the same variable.
+
=head1 RETURN VALUES
BN_is_bit_set() returns 1 if the bit is set, 0 otherwise.