Explanation of ew_from_su2_u1
(1) In plain English, the declaration states that the electroweak rank equals the sum of the SU(2) rank and the U(1) rank. It holds immediately by the definition of rankEW as that sum.
(2) In Recognition Science this matters because the framework identifies the electroweak group SU(2)×U(1) with total rank 3, matching the spatial dimension D forced by the topology of circle linking. The module presents this as a structural bridge between gauge ranks and the D=3 result.
(3) The formal statement is:
theorem ew_from_su2_u1 : rankEW = rankSU2 + rankU1 := rfl
rankSU2 and rankU1 are defined as the constants 2 and 1; rankEW is defined as their sum. The proof rfl is reflexivity after unfolding the definition.
(4) Visible dependencies in the supplied source are the three definitions rankSU2, rankU1, and rankEW, the theorem rankEW_eq_D that sets the sum to 3, the inductive type EWObservable with five constructors, and the theorem ewObservableCount. The value is packaged in the certificate electrowealCert via the rank_sum field.
(5) The declaration does not prove any dynamical unification, the ~100 GeV scale, a J-cost threshold for field splitting, or the emergence of the gauge groups from recognition cost. It is a pure rank-arithmetic identity; the module docstring mentions these further elements only as context.