Definition df-mo 1422

Description: Define "there exists at most one x such that ph." Here we define it in terms of existential uniqueness. Notation of [BellMachover] p. 460, whose definition we show as mo3 1440. For other possible definitions see mo2 1439 and mo4 1442.

Assertion

Ref	Expression
df-mo	|- (E*xph <-> (E.xph -> E!xph))

Detailed syntax breakdown of Definition df-mo

Step	Hyp	Ref	Expression
1		wph	. . 3 wff ph
2		vx	. . 3 set x
3	1, 2	wmo 1420	. 2 wff E*xph
4	1, 2	wex 1016	. . 3 wff E.xph
5	1, 2	weu 1419	. . 3 wff E!xph
6	4, 5	wi 3	. 2 wff (E.xph -> E!xph)
7	3, 6	wb 144	1 wff (E*xph <-> (E.xph -> E!xph))

This definition is referenced by:  mo2 1439  mobid 1443  hbmo1 1445  hbmo 1446  cbvmo 1447  exmoeu 1452  moabs 1454  exmo 1455  moeq 1966

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