diff --git a/fixed.tal b/fixed.tal
index 136e677..21eb1ec 100644
--- a/fixed.tal
+++ b/fixed.tal
@@ -5,6 +5,13 @@
 ( )
 ( x = x0 + x1/256 )
 ( y = y0 + y1/256 )
+( )
+( many 8.8 operations are equivalent to u16: )
+(   * comparisons/equality )
+(   * addition/subtraction )
+( )
+( but due to 16-bit truncation multiplication is different. )
+( )
 ( x*y = x0*y0 + x0*y1/256 + x1*y0/256 + x1*y1/65536 )
 ( )
 ( since we only have 16-bits: )