Introduction to Algorithms/Variables

In the above example it is fairly simple to follow the piece of toast through the algorithm, but if you imagine that the algorithm could become more complex, and thus the progress of the toast much harder to follow. In order that, at any point in the algorithm, it is clear what is being talked about, names are often given to things. For example

Algorithm for making buttered toast (3.0)

 LET A = a loaf of bread
 LET T = a toaster
 LET P = a plate
 LET B = some butter
 LET S = cut slice from A
 get A
 move the S to T
 turn on T
 wait for T
 move the S to P
 spread S with B