theorem srecauxeq2 (S: set) (_n1 _n2: nat): $ _n1 = _n2 -> srecaux S _n1 = srecaux S _n2 $;
_n1 = _n2 -> _n1 = _n2
_n1 = _n2 -> srecaux S _n1 = srecaux S _n2