God Plays Coins or Superposition Principle for Classical Probabilities in Quantum Suprematism Representation of Qubit States

We construct the quantum density matrix of a spin-1/2 state for three given probability distributions describing positions of three classical coins and associate its matrix elements with the Triada of Malevich’s squares. We present the superposition principle of spin-1/2 states in the form of a nonlinear addition rule for these classical coin probabilities. We illustrate the obtained formulas by the statement “God does not play dice – God plays coins.”