Water batons do not dip their op amps in blackwater ponds.... Not around the op amp, but on the line what is supposed to connect to the triangle thingy... (OP amp symbol has a line with a circle at the triangle where the line connects)
When these are on a network in regular schematic, they represent terminators of various types.. especially in differentials
But dearly exposed, and hand drawn circuits are already very confining, they would as it was, probably mark actual connection to the operational amplifier... That is on the places oneust connect to it. Maybe.
Then in a diodic circuit they could mark the polarity involved at any specific point in the operating system.