otherwise; if not; or (else)
否 · 7 strokes
Originally the same character as 不. Distinguishing component 口 was added later to the character when it took on the meaning "not". 不 represents the sound.
则 · 6 strokes
Simplified form of 則. Depicts carving inscriptions on bronzeware (鼎) with a knife (刂). Based on the original meaning "law". In ancient China, some legal writings were inscribed on bronzeware.