Definition df-stab 833

Description: Propositions where a double-negative can be removed are called stable. See Chapter 2 [Moschovakis] p. 2.

Our notation for stability is a connective STAB which we place before the formula in question. For example, STAB x = y corresponds to " x = y is stable".

(Contributed by David A. Wheeler, 13-Aug-2018.)

Assertion

Ref	Expression
df-stab	|- (STAB ph <-> ( -. -. ph -> ph ) )

Detailed syntax breakdown of Definition df-stab

Step	Hyp	Ref	Expression
1		wph	. . 3 wff ph
2	1	wstab 832	. 2 wff STAB ph
3	1	wn 3	. . . 4 wff -. ph
4	3	wn 3	. . 3 wff -. -. ph
5	4, 1	wi 4	. 2 wff ( -. -. ph -> ph )
6	2, 5	wb 105	1 wff (STAB ph <-> ( -. -. ph -> ph ) )

This definition is referenced by:  stbid  834  stabnot  835  dcstab  846  stdcndc  847  stdcndcOLD  848  stdcn  849  const  854  imanst  890  ddifstab  3313  exmid1stab  4268  2omotap  7406  bj-trst  15875  bj-fast  15877  bj-nnbist  15880  bj-stim  15882  bj-stan  15883  bj-stand  15884  bj-stal  15885  bj-pm2.18st  15886  bj-con1st  15887  bdstab  15962  subctctexmid  16139