Subject: Count Looping From: "William J. Rapaport" Date: Sun, 21 Feb 2010 20:42:28 -0500 (EST) A student writes: "In your description of count looping in the paper you handed out, you used the conditional? y<--- y-1. Does that mean 'if value is >0 then subtract by 1'? And then I suppose it will continue the program until the value=0?" Reply: No: "y <- y-1" means that the current value of y is replaced by the current value - 1. So if y=10 before this statement is executed, then y=9 after it is executed. The "<-" is an assignment operator; some programming languages use ":=" instead. The student continues: "And just to make sure, in the categories of structured programs, all count programs are while programs, and in the categories of functions some while-recursive functions and all primitive-recursive functions are partial-recursive functions are correct?" Reply: Yes, all count-programs are while-programs, some while-recursive functions are partial-recursive, and all primitive-recursive functions are partial-recursive.