1. a : LOSet
2. b : AbDGrp
3. ps : |oal(a;b)|
⊢ map(λz.(fst(z));ps) ≡(|a|) map(λz.(fst(z));--ps)
{ ((StrengthenRel) THENA Auto) }
⊢ map(λz.(fst(z));ps) = map(λz.(fst(z));--ps) ∈ (|a| List)