For the implication A B, Frege used a notation which was placed across two lines with A being written on the line below B. It is not hard to see why his notation has not survived, but we should not allow this in any way to diminish the magnitude of his achievement.
For mõjuta B Frege kasutada märke, mis kanti üle kahe read on kirjutatud rida allpool B. Ei ole raske mõista, miks tema märke ei ole säilinud, kuid me ei tohiks anda see kuidagi vähendada suurusjärgus tema saavutus.