math stuff

1 files changed, 33 insertions, 6 deletions

diff --git a/readme.md b/readme.md
index 43b0da8..7e93f2f 100644
--- a/readme.md
+++ b/readme.md
@@ -1,7 +1,6 @@
 # sanctuary (working title)
 
-sanctuary is a 64-bit subroutine threaded forth system
-for amd64 linux systems.
+sanctuary is a 64-bit subroutine threaded forth for amd64 linux systems.
 
 ## stack effect notation
 
@@ -26,6 +25,26 @@ create a dictionary header for a word named the provided string.
 this word does not set the code field.
 this word returns an incompleted xt and does not update latest.
 
+### `*   ( u1 u2 -- u)`
+multiply u1 and u2.
+
+### `*/mod   ( n1 n2 n3 -- n4 n5 )`
+multiply n1 and n2, divide the result by n3.
+remainder is in n3, result is in n4
+
+### `+   ( u1 u2 -- u )`
+add u2 to u1.
+
+### `-   ( u1 u2 -- u )`
+subtract u2 from u1.
+
+### `-rot   ( u1 u2 u3 -- u3 u1 u2 )`
+rotate the three topmost values on the stack so that the topmost value
+is moved to the third highest.
+
+### `/mod   ( u1 u2 -- u3 u4 )`
+divide u1 by u2. result is in u4, remainder is in u3.
+
 ### `[   ( -- ) IMMEDIATE`
 set the system to interpret mode.
 
@@ -38,10 +57,6 @@ start compilation of the word 'name'.
 ### `;   ( -- ) IMMEDIATE`
 end compilation of the currently compiling word.
 
-### `-rot   ( u1 u2 u3 -- u3 u1 u2 )`
-rotate the three topmost values on the stack so that the topmost value
-is moved to the third highest.
-
 ### `>body   ( xt -- a )`
 yield the code field of xt.
 
@@ -58,6 +73,9 @@ remove the two topmost values from the stack.
 ### `2dup   ( u1 u2 -- u1 u2 u1 u2 )`
 duplicate the two topmost values on the stack.
 
+### `and   ( u1 u2 -- u )`
+perform bitwise AND on u1 and u2.
+
 ### `brk@   ( -- a )`
 yields current program break.
 
@@ -103,6 +121,9 @@ true if xt is marked immediate, false otherwise.
 interprets the contents of the terminal input buffer
 until it runs out.
 
+### `invert   ( u -- u')`
+invert all bytes in u.
+
 ### `latest   ( -- a )`
 a variable containing the execution token of
 the most recently created word.
@@ -115,6 +136,9 @@ convert given string into a number along with a flag.
 if parsing a number fails then 0 (false) is returned
 and no number is provided.
 
+### `or  ( u1 u2 -- u )`
+perform bitwise OR on u1 and u2.
+
 ### `parse   ( "name<c>" c -- a u )`
 parse one word from the input buffer,
 separated by a newline or the character c,
@@ -174,6 +198,9 @@ write u characters at a to output.
 ### `over   ( u1 u2 -- u1 u2 u1 )`
 copy the second-highest value on the stack and move it to the top of the stack.
 
+### `xor   ( u1 u2 -- u )`
+perform bitwise XOR on u1 and u2.
+
 ## dictionary format
 
 note that the string length of one byte limits a word's name to 255 characters.