Nuprl Lemma : sym_shift 13,42

AB:Type, R:(AA), S:(BB), f:(AB).
RelsIso(A;B;x,y.R(x,y);x,y.S(x,y);f Sym(B;x,y.S(x,y))  Sym(A;x,y.R(x,y)) 
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Upgen algebra 1
Definitions of StatementRelsIso(T;T';x,y.R(x;y);x,y.R'(x;y);f)
Definitionsx,yt(x;y), t  T, Sym(T;x,y.E(x;y)), x(s1,s2), P  Q, , x:AB(x), RelsIso(T;T';x,y.R(x;y);x,y.R'(x;y);f), P  Q, P & Q, P  Q
Lemmasrels iso wf, sym wf

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