I think it's a logic diagram, not an electrical symbol. For anyone looking for an explanation of the newer symbol, this is a nice source: https://www.petervis.

I think it's a logic diagram, not an electrical symbol. For anyone looking for an explanation of the newer symbol, this is a nice source: https://www.petervis.com/electronics/MOSFET_Symbol/MOSFET_Symbol.html https://www.petervis.com/electronics/MOSFET_Symbol/MOSFET_Sy... Arrows were used in 1975, see page 57: https://www.noao.edu/ets/Mechanical/Policies/ANSI%20Y32.2-1975.pdf https://www.noao.edu/ets/Mechanical/Policies/ANSI%20Y32.2-19...