There are lots of schematics of minecraft circuits online, but few of them reference the notation they are using and I am finding it hard to chase down what some symbols mean.
For example Layer 0 of a shift register here:
has squares with grey and red/grey triangles in them. I have no idea what they are supposed to be.
On the wiki itself there are weird triangular things as well, for instance a diagram of an edge detector (http://minecraft.gamepedia.com/Pulse_circuit#Edge_detector) has things I don't understand in it.
Is there a reference for these notations somewhere? (I am trying to make a simple 2 bit shift register as it happens).