Definition df-vd3

Description: Definition of a 3-hypothesis virtual deduction. (Contributed by Alan Sare, 14-Nov-2011) (New usage is discouraged.)

	Ref	Expression
Assertion	df-vd3	$$⊢\left(\phi ,\psi ,\chi \to \theta \right)\leftrightarrow \left(\left(\phi \wedge \psi \wedge \chi \right)\to \theta \right)$$

Detailed syntax breakdown

Step	Hyp	Ref	Expression
0		wph	$$wff\phi$$
1		wps	$$wff\psi$$
2		wch	$$wff\chi$$
3		wth	$$wff\theta$$
4	0 1 2 3	wvd3	$$wff\left(\phi ,\psi ,\chi \to \theta \right)$$
5	0 1 2	w3a	$$wff\left(\phi \wedge \psi \wedge \chi \right)$$
6	5 3	wi	$$wff\left(\left(\phi \wedge \psi \wedge \chi \right)\to \theta \right)$$
7	4 6	wb	$$wff\left(\left(\phi ,\psi ,\chi \to \theta \right)\leftrightarrow \left(\left(\phi \wedge \psi \wedge \chi \right)\to \theta \right)\right)$$