Confused about indexing into lists...

[webmasterpdx]

My understanding was that in CAS mode, lists should be indexed using square brackets to avoid confusion with function calls, so I tried the following....

L1:={1,2,3,4,5,6,7,8,9}

When in Home mode, I can type L1(3) or L1[3] and I'll get 3 back....correct...both braces work.

Now, go to CAS mode.

L1(3) works and returns 3...so next I tried the square brackets...

L1[3] gets converted to at(L1,2) and {1,2,3,4,5,6,7,8,9} gets returned??????

So, then I typed...

at(L1,2) and it returned at({1,2,3,4,5,6,7,8,9},2) ????

So, what am I doing wrong?