Theorem con2d 151

Description: A contraposition deduction.

Hypotheses

Ref	Expression
con2d.1	|- T:*
con2d.2	|- (R, S) |= (~ T)

Assertion

Ref	Expression
con2d	|- (R, T) |= (~ S)

Proof of Theorem con2d

Step	Hyp	Ref	Expression
1		con2d.1	. . . . 5 |- T:*
2		wfal 125	. . . . 5 |- F.:*
3		con2d.2	. . . . . 6 |- (R, S) |= (~ T)
4	3	ax-cb1 29	. . . . . . 7 |- (R, S):*
5	1	notval 135	. . . . . . 7 |- T. |= [(~ T) = [T ==> F.]]
6	4, 5	a1i 28	. . . . . 6 |- (R, S) |= [(~ T) = [T ==> F.]]
7	3, 6	mpbi 72	. . . . 5 |- (R, S) |= [T ==> F.]
8	1, 2, 7	imp 147	. . . 4 |- ((R, S), T) |= F.
9	8	an32s 55	. . 3 |- ((R, T), S) |= F.
10	9	ex 148	. 2 |- (R, T) |= [S ==> F.]
11	4	wctl 31	. . . 4 |- R:*
12	11, 1	wct 44	. . 3 |- (R, T):*
13	4	wctr 32	. . . 4 |- S:*
14	13	notval 135	. . 3 |- T. |= [(~ S) = [S ==> F.]]
15	12, 14	a1i 28	. 2 |- (R, T) |= [(~ S) = [S ==> F.]]
16	10, 15	mpbir 77	1 |- (R, T) |= (~ S)

Syntax hints:  *hb 3  kc 5   = ke 7  [kbr 9  kct 10   |= wffMMJ2 11  wffMMJ2t 12  F.tfal 108  ~ tne 110   ==> tim 111

This theorem was proved from axioms:  ax-syl 15  ax-jca 17  ax-simpl 20  ax-simpr 21  ax-id 24  ax-trud 26  ax-cb1 29  ax-cb2 30  ax-refl 39  ax-eqmp 42  ax-ded 43  ax-ceq 46  ax-beta 60  ax-distrc 61  ax-leq 62  ax-distrl 63  ax-hbl1 93  ax-17 95  ax-inst 103

This theorem depends on definitions:  df-ov 65  df-al 116  df-fal 117  df-an 118  df-im 119  df-not 120

This theorem is referenced by:  con3d  152  exnal1  175