The condition (?=b) must return false.
It does. The condition returns false, therefore it make no attempt to match the (null) yes pattern (which would have matched anyway), and simply moves on to the next element 'a$', which matches.
In other words, if the condition of the conditional expression, in this case the lookahead assertion, is false, then no attempt is made to use either the yes pattern, or the no pattern (here missing). In effect, the entire construct becomes a noop.
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
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