fact: Definition addℝ_switch := λ"XY" "XY" @ λ"ε₁" λ"ε₂" λ"q₁" λ"q₂" λ"X" λ"Y" λ"f" "f" @ "ε₂" @ "ε₁" @ "q₂" @ "q₁" @ "Y" @ "X".
imports: QArith Psatz ClassicalRealizability.Kbase ClassicalRealizability.Rationals ClassicalRealizability.Real_definitions ClassicalRealizability.Real_relations