The Godel formula

• “There exists a formula with Godel number M which possesses the property that the formula has no proof.”
• Replace M by “Subst(x,x)”
• “There exists a formula with Godel number Subst(x,x) which possesses the property that the formula has no proof.”
• Let us abbreviate the above as:
• F( Subst(x,x) )