fix(mylogic.sty): add \inv, for algebra chapter
fix(mylogic.sty): add \inv, for algebra chapter

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