Open Mttbnchtt opened 6 months ago
Consider the following rules:
(WRONG RULE) if P is a property, xPy, and x is in proof step z, then y is in proof step z
(WRONG RULE) if P is a property, yPx, and x is in proof step z, then y is in proof step z
THIS RULES ARE FALSE (e.g. consider P = different-from). HOWEVER, THE RULES HOLDS FOR A LARGE CLASS OF PROPERTIES. BUT WHICH CLASS EXACTLY?
Consider the following rules:
(WRONG RULE) if P is a property, xPy, and x is in proof step z, then y is in proof step z
(WRONG RULE) if P is a property, yPx, and x is in proof step z, then y is in proof step z
THIS RULES ARE FALSE (e.g. consider P = different-from). HOWEVER, THE RULES HOLDS FOR A LARGE CLASS OF PROPERTIES. BUT WHICH CLASS EXACTLY?