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(a|ε)bNo ? quantifier — use (r|ε)vs Programming RegexFormal RE✨ Emoji Combos

Programming regex: a?b. Formal RE: (a|ε)b. The ? quantifier is defined as r? ≡ (r|ε). Formal RE makes this explicit.

✓ Accepts
bab
✗ Rejects
εaabbaabb
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