 # Introduction to Propositional Logic in Minecraft

“What are logic gates?” That is a question I am asked a lot. That’s why I created this instruction.

Basically, logic gates are modular building blocks that can be used to contact bigger, more complex machines. Logic gates can start to be useful when you ask yourself simple questions like:

• I would like to be able to toggle the lights from two separate switches in my Minecraft house.
• Three separate inputs must be turned on, in order to open a secret door in my adventure map.

Logic gates are the basic blocks for logical operations. You might not even notice that “mathematical logic” was involved in these questions mentioned above. But it actually is. That‘s why it‘s super-useful to learn about the basics of Electrical Engineering and Computer Science, it can save you a lot of time when working on Redstone mechanisms in Minecraft.

This may sound a little complicated firstly, on closer inspection, however, it is somewhat easier to understand:

• Each logic gate has multiple signal inputs and one output signal output
• the output signal can be either positive (on) or negative (off)
• the condition for the status of the output signal is the gate itself
• the gate combines the input signals and calculates the output
Do not worry, follow the examples on the following pages!

Now let us take as an example the “OR gate”. The condition for a positive output signal is in the name: “or” means that at least one input must be positive so that the output signal is positive.

Another example: the “exclusive OR gate.”
…there seems no difference to the “OR gate”, however, the “exclusive” means that the maximum number of positive input signals is limited to one to produce a positive output signal.

A “non-or gates” describes a logic gate, which requires as a condition for a positive output signal that no single input signal must be positive.