Definition df-stab 836

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 835	. 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  837  stabnot  838  dcstab  849  stdcndc  850  stdcndcOLD  851  stdcn  852  const  857  imanst  893  ddifstab  3336  exmid1stab  4291  2omotap  7441  bj-trst  16061  bj-fast  16063  bj-nnbist  16066  bj-stim  16068  bj-stan  16069  bj-stand  16070  bj-stal  16071  bj-pm2.18st  16072  bj-con1st  16073  bdstab  16148  subctctexmid  16325