Abstract
The assumptions that (1) the weak processes BB, MM (ΔS=±1) are mediated by an interaction that transforms like λ6, (2) the nonleptonic decay amplitudes of hyperons are dominated by pole terms, and (3) the mass-splitting pattern of the baryon octet can be approximated by m=m0+(Δm)Y imply that the effective Lagrangian describing the parity-conserving hyperon decays transforms like λτ under SU(3). The sum rule 2P(Ξ)=P(Λ0)+3P(Σ0+) follows immediately from this observation.