1 files changed, 47 insertions, 0 deletions
diff --git a/runtime/macros/urm/README.txt b/runtime/macros/urm/README.txt
new file mode 100644
index 0000000..a1ecc65
--- /dev/null
+++ b/runtime/macros/urm/README.txt
@@ -0,0 +1,47 @@
+This is another proof that Vim is perfectly compatible with Vi.
+The URM macro package was written by Rudolf Koenig ("Rudi")
+(rudolf@koeniglich.de) for hpux-vi in August 1991.
+
+Getting started:
+
+type
+in your shell:	 vim urm<RETURN>
+in vim:		 :so urm.vim<RETURN>
+in vim:		 *	(to load the registers and boot the URM-machine :-)
+in vim:		 g	(for 'go') and watch the fun. Per default, 3 and 4
+			are multiplied. Watch the Program counter, it is
+			visible as a komma moving around.
+
+This is a "standard URM" (Universal register machine)  interpreter. The URM
+concept is used in theoretical computer science to aid in theorem proving.
+Here it proves that vim is a general problem solver (if you bring enough
+patience).
+
+The interpreter begins with register 1 (not 0), without macros and more-lines
+capability.  A dot marks the end of a program. (Bug: there must be a space
+after the dot.)
+
+The registers are the first few lines, beginning with a '>' .
+The program is the first line after the registers.
+You should always initialize the registers required by the program.
+
+Output register:	line 2
+Input registers:	line 2 to ...
+
+Commands:
+a<n>		increment register <n>
+s<n>		decrement register <n>
+<x>;<y>		execute command <x> and then <y>
+(<x>)<n>	execute command <x> while register <n> is nonzero
+. 		("dot blank")  halt the machine.
+
+Examples:
+
+Add register 2 to register 3:
+	(a2;s3)3.
+Multiply register 2 with register 3:
+	(a4;a5;s2)2; ((a2;s4)4; s3; (a1;a4;s5)5; (a5;s1)1)3.
+
+There are more (complicated) examples in the file examples.
+Note, undo may take a while after a division.
+