dc unix : preserving initial value even after storing new value at the same array index

I'm unable to understand this example given in manpage of dc: $ dc 1 0:a 0Sa 2 0:a La 0;ap 1 To me answer should be 2 because: 1. 1 0:a Here we store 1 at 0th position of array a. 2. 0Sa Now we push 0 to the stack of register a. 3. 2 0:a Now here again we store 2 at 0th position of array a thereby overwriting the previous 1 stored at that location. 4. La Now we pop the 0 stored on stack of register a and push it to main stack. 5. 0;a Now we again push 0 to the main stack and then pop it to use as an array index and so we push the 2 stored at 0th location of array a to the main stack. 6. p Now we print the top of main stack which is 2. So answer should be 2. What am I missing? PS- I wanted to use dc as a tag but looks like it doesn't exist and it's compulsory to use at least one tag so used debian (my workstation OS).