+$x = $class->new(8);
+$y = $class->new(-1);
+$z = $class->new(5033);
+my $u = $x->copy()->bmodpow($y,$z);
+ok ($u,4404);
+ok ($y,-1);
+ok ($z,5033);
+
+$x = $class->new(-5); $y = -$x; ok ($x,-5); ok ($y,5);
+$x = $class->new(-5); $y = $x->copy()->bneg(); ok ($x,-5); ok ($y,5);
+
+$x = $class->new(-5); $y = $class->new(3); $x->bmul($y); ok ($x,-15); ok ($y,3);
+$x = $class->new(-5); $y = $class->new(3); $x->badd($y); ok ($x,-2); ok ($y,3);
+$x = $class->new(-5); $y = $class->new(3); $x->bsub($y); ok ($x,-8); ok ($y,3);
+$x = $class->new(-15); $y = $class->new(3); $x->bdiv($y); ok ($x,-5); ok ($y,3);
+$x = $class->new(-5); $y = $class->new(3); $x->bmod($y); ok ($x,1); ok ($y,3);
+
+$x = $class->new(5); $y = $class->new(3); $x->bmul($y); ok ($x,15); ok ($y,3);
+$x = $class->new(5); $y = $class->new(3); $x->badd($y); ok ($x,8); ok ($y,3);
+$x = $class->new(5); $y = $class->new(3); $x->bsub($y); ok ($x,2); ok ($y,3);
+$x = $class->new(15); $y = $class->new(3); $x->bdiv($y); ok ($x,5); ok ($y,3);
+$x = $class->new(5); $y = $class->new(3); $x->bmod($y); ok ($x,2); ok ($y,3);
+
+$x = $class->new(5); $y = $class->new(-3); $x->bmul($y); ok ($x,-15); ok($y,-3);
+$x = $class->new(5); $y = $class->new(-3); $x->badd($y); ok ($x,2); ok($y,-3);
+$x = $class->new(5); $y = $class->new(-3); $x->bsub($y); ok ($x,8); ok($y,-3);
+$x = $class->new(15); $y = $class->new(-3); $x->bdiv($y); ok ($x,-5); ok($y,-3);
+$x = $class->new(5); $y = $class->new(-3); $x->bmod($y); ok ($x,-1); ok($y,-3);
+
+###############################################################################