fix(19): typos and wording
fix(19): typos and wording

avigad/logic_and_proof,rlewis1988/logic_and_proof,rlewis1988/logic_and_proof,fpvandoorn/logic_and_proof,fpvandoorn/logic_and_proof,leanprover/logic_and_proof,rlewis1988/logic_and_proof,leanprover/logic_and_proof,leanprover/logic_and_proof,avigad/logic_and_proof,avigad/logic_and_proof,fpvandoorn/logic_and_proof