well actually, here is the real math behind +1
So if /*!)-*&~n/{"isRoot":false,"isTextMode":false,"isTabularCellsSelected":false,"isPureText":false,"insideInlineMath":false,"lines":[{"blocks":[{"text":"a"},{"text":"\\index","type":"composite","elements":{"indexValue":{"lines":[{"blocks":[{"text":"1"}]}]}}}]}],"rootEditorId":"321241621323","inlineMathDisplayStyle":null}
equals to
/*!)-*&~n/{"isRoot":false,"isTextMode":false,"isTabularCellsSelected":false,"isPureText":false,"insideInlineMath":false,"lines":[{"blocks":[{"text":"\\frac","type":"composite","elements":{"value":{"lines":[{"blocks":[{"text":"a"}]}]},"sub1":{"lines":[{"blocks":[{"text":"b"}]}]}}}]}],"rootEditorId":"321241621323","inlineMathDisplayStyle":null}
that means that +1 is actually shorter than agree.