theorem sreceq2d (_G: wff) (S: set) (_n1 _n2: nat): $ _G -> _n1 = _n2 $ > $ _G -> srec S _n1 = srec S _n2 $;
_G -> S == S
_G -> _n1 = _n2
_G -> srec S _n1 = srec S _n2