$ pl -s alzint.pl -g "run('ex3.txt')"

 ==>  while x >= 2 do
        begin
         f <- f * x
        ;
         x <- x - 1
        end

     f = 1   x = 10   
----------------------------------------------------------------------



      while x >= 2 do
        begin
 ==>     f <- f * x
        ;
         x <- x - 1
        end

     f = 1   x = 10   
----------------------------------------------------------------------



      while x >= 2 do
        begin
         f <- f * x
        ;
 ==>     x <- x - 1
        end

     f = 10   x = 10   
----------------------------------------------------------------------



 ==>  while x >= 2 do
        begin
         f <- f * x
        ;
         x <- x - 1
        end

     f = 10   x = 9   
----------------------------------------------------------------------



      while x >= 2 do
        begin
 ==>     f <- f * x
        ;
         x <- x - 1
        end

     f = 10   x = 9   
----------------------------------------------------------------------



      while x >= 2 do
        begin
         f <- f * x
        ;
 ==>     x <- x - 1
        end

     f = 90   x = 9   
----------------------------------------------------------------------



 ==>  while x >= 2 do
        begin
         f <- f * x
        ;
         x <- x - 1
        end

     f = 90   x = 8   
----------------------------------------------------------------------



      while x >= 2 do
        begin
 ==>     f <- f * x
        ;
         x <- x - 1
        end

     f = 90   x = 8   
----------------------------------------------------------------------



      while x >= 2 do
        begin
         f <- f * x
        ;
 ==>     x <- x - 1
        end

     f = 720   x = 8   
----------------------------------------------------------------------



 ==>  while x >= 2 do
        begin
         f <- f * x
        ;
         x <- x - 1
        end

     f = 720   x = 7   
----------------------------------------------------------------------



      while x >= 2 do
        begin
 ==>     f <- f * x
        ;
         x <- x - 1
        end

     f = 720   x = 7   
----------------------------------------------------------------------



      while x >= 2 do
        begin
         f <- f * x
        ;
 ==>     x <- x - 1
        end

     f = 5040   x = 7   
----------------------------------------------------------------------



 ==>  while x >= 2 do
        begin
         f <- f * x
        ;
         x <- x - 1
        end

     f = 5040   x = 6   
----------------------------------------------------------------------



      while x >= 2 do
        begin
 ==>     f <- f * x
        ;
         x <- x - 1
        end

     f = 5040   x = 6   
----------------------------------------------------------------------



      while x >= 2 do
        begin
         f <- f * x
        ;
 ==>     x <- x - 1
        end

     f = 30240   x = 6   
----------------------------------------------------------------------



 ==>  while x >= 2 do
        begin
         f <- f * x
        ;
         x <- x - 1
        end

     f = 30240   x = 5   
----------------------------------------------------------------------



      while x >= 2 do
        begin
 ==>     f <- f * x
        ;
         x <- x - 1
        end

     f = 30240   x = 5   
----------------------------------------------------------------------



      while x >= 2 do
        begin
         f <- f * x
        ;
 ==>     x <- x - 1
        end

     f = 151200   x = 5   
----------------------------------------------------------------------



 ==>  while x >= 2 do
        begin
         f <- f * x
        ;
         x <- x - 1
        end

     f = 151200   x = 4   
----------------------------------------------------------------------



      while x >= 2 do
        begin
 ==>     f <- f * x
        ;
         x <- x - 1
        end

     f = 151200   x = 4   
----------------------------------------------------------------------



      while x >= 2 do
        begin
         f <- f * x
        ;
 ==>     x <- x - 1
        end

     f = 604800   x = 4   
----------------------------------------------------------------------



 ==>  while x >= 2 do
        begin
         f <- f * x
        ;
         x <- x - 1
        end

     f = 604800   x = 3   
----------------------------------------------------------------------



      while x >= 2 do
        begin
 ==>     f <- f * x
        ;
         x <- x - 1
        end

     f = 604800   x = 3   
----------------------------------------------------------------------



      while x >= 2 do
        begin
         f <- f * x
        ;
 ==>     x <- x - 1
        end

     f = 1814400   x = 3   
----------------------------------------------------------------------



 ==>  while x >= 2 do
        begin
         f <- f * x
        ;
         x <- x - 1
        end

     f = 1814400   x = 2   
----------------------------------------------------------------------



      while x >= 2 do
        begin
 ==>     f <- f * x
        ;
         x <- x - 1
        end

     f = 1814400   x = 2   
----------------------------------------------------------------------



      while x >= 2 do
        begin
         f <- f * x
        ;
 ==>     x <- x - 1
        end

     f = 3628800   x = 2   
----------------------------------------------------------------------



 ==>  while x >= 2 do
        begin
         f <- f * x
        ;
         x <- x - 1
        end

     f = 3628800   x = 1   
----------------------------------------------------------------------