Discussion on question by thinkingman: Can a zero prior probability for some theories be justified?

@thinkingman: In some programming languages, variables can take some variation of Nul/Null/None/NA/NaN value. There is the normal number line, and a special exception value. You seem to be using P=0 in a similar manner, to say "Oh, I haven't even accepted it might have a probability. I will consider assigning one when I have some evidence presented", where others are using it to mean "There is absolutely no chance this could ever be true; trying to introduce evidence is pointless."