Naive Factorial Program

The following is a valid µOCCAM program that performs I/O. A simple program to calculate the factorial of a number. It outputs the value at each stage, therefore the last value outputed is the result.

Program file: /public/cs3/web/ipptests/fact.io

INT x:
INT fact:

SEQ
  stdin ? x
  fact := x
  WHILE x<>1
    SEQ 
      x:=x-1
      fact := fact * x
      stdout ! fact

When provided with this input: /public/cs3/web/ipptests/fact.in

5

it should generate the following output: /public/cs3/web/ipptests/fact.out

==> 20
==> 60
==> 120