in reply to two + 2 not equal 4!
If you replace your last line with
printf "two + 2 = %d\n",&two + 2;
(note the ampersand) you get "two + 2 = 4". So it seems the parser treats your "two" as a bareword and converts it to 0 in numeric context (therefore the result).
I wonder why this does not procuce a warning though...
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