Hmm. Just checked again. Two of the expressions match neither word, one matches both, and one matches only one. EDIT: I see. The confusion is over partial matc

Hmm. Just checked again. Two of the expressions match neither word, one matches both, and one matches only one. EDIT: I see. The confusion is over partial match vs whole match. I thought whole matches were standard when talking about regular expression in the abstract, but looks like I was wrong. Just changed the problem to include the anchors. Thanks for pointing this out.