If I didn't write Preschool Engineering I probably would have just shook it off. She is, after all, a three year old who talks incessantly about all sorts of things. But my training is as an electrical engineer and something was resonating with memories of some ancient coursework...she was exploring logic.
This and that, that or this, not the other thing. I guess learning logic begins at a very early age. Mom and Dad being at home together means something different from Mom or Dad being around. Mom and Dad but not brother means something else. No doubt, each social scenario has different emotional connotations to it for a young child. So I suppose it makes sense that young children spend some time making sense of permutations of how stuff combines or doesn't.
And as I write this I am thinking about how logic underlies so much preschool learning. Color learning, cooking, bathtub play all have AND, OR, or NOT aspects to them. Red AND blue make purple. Water OR milk loosen the pancake batter. Baby doll NOT rock floats. Truly, it is unbelievable the capacity and rate at which a playful child can learn!