Having a lot of fun with the LOOP language.

The language (see here) is simple:

*Variables: x0,x1,x2,x3,x4,...*

*Constants: 0,1,2,3,4,...*

*Operators: + and -*

*Separators: ; and :=*

*Keywords: LOOP,DO and END*

And if you let xi and xj be variables and let c be a constant. Then

**xi := xj + c**

and

**xi := xj - c**

are correct programs.

Let P1 and P2 be LOOP programs. Then

**P1; P2**

is a LOOP Program.

Let P be a LOOP program and let xi be a variable. Then

**LOOP xi DO P END**

is a LOOP Program.

=)(==)(==)(==)(==)(==)(==)(==)(==)(==)(==)(==)(==)(==)(==)(==)(==)(==)(==)(==)(=

This program for example:

x3 := x1 + 0;

LOOP x2 DO

x3 := x3 + 1

END;

x0 := x3 + 0

shows that f(x1+x2) = x1+x2 is LOOP-computable (with strict LOOP).

If you give input parameters like: 5,3

the output will be: 8