This non-implication, 
	Form 419 \( \not \Rightarrow \)
	Form 253, 
	 whose code is 4,  is constructed around a proven non-implication as follows:
	
| Hypothesis | Statement | 
|---|---|
| Form 345 | <p> <strong>Rasiowa-Sikorski Axiom:</strong> If \((B,\land,\lor)\) is a Boolean algebra, \(a\) is a non-zero element of \(B\), and \(\{X_n: n\in\omega\}\) is a denumerable set of subsets of \(B\) then there is a maximal filter \(F\) of \(B\) such that \(a\in F\) and for each \(n\in\omega\), if \(X_n\subseteq F\) and \(\bigwedge X_n\) exists then \(\bigwedge X_n \in F\). </p> | 
| Conclusion | Statement | 
|---|---|
| Form 253 | <p> <strong>\L o\'s' Theorem:</strong> If \(M=\langle A,R_j\rangle_{j\in J}\) is a relational system, \(X\) any set and \({\cal F}\) an ultrafilter in \({\cal P}(X)\), then \(M\) and \(M^{X}/{\cal F}\) are elementarily equivalent. </p> | 
The conclusion Form 419 \( \not \Rightarrow \) Form 253 then follows.
	Finally, the 
	  List of models where hypothesis is true and the conclusion is false:
	  	
| Name | Statement | 
|---|---|
| \(\cal M40(\kappa)\) Pincus' Model IV | The ground model \(\cal M\), is a model of \(ZF +\) the class form of \(AC\) | 
| \(\cal N40\) Howard/Rubin Model II | A variation of \(\cal N38\) |