### Nuprl Lemma : or_functionality_wrt_uiff3

`∀[P1,P2,Q1,Q2:ℙ].  ((P1 = P2 ∈ ℙ) `` {uiff(Q1;Q2)} `` {P1 ∨ Q1 `⇐⇒` P2 ∨ Q2})`

Proof

Definitions occuring in Statement :  uiff: `uiff(P;Q)` uall: `∀[x:A]. B[x]` prop: `ℙ` guard: `{T}` iff: `P `⇐⇒` Q` implies: `P `` Q` or: `P ∨ Q` equal: `s = t ∈ T`
Definitions unfolded in proof :  guard: `{T}` uall: `∀[x:A]. B[x]` implies: `P `` Q` uiff: `uiff(P;Q)` and: `P ∧ Q` iff: `P `⇐⇒` Q` or: `P ∨ Q` prop: `ℙ` member: `t ∈ T` uimplies: `b supposing a` rev_implies: `P `` Q`
Lemmas referenced :  or_wf uiff_wf equal_wf
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep Error :isect_memberFormation_alt,  lambdaFormation sqequalHypSubstitution productElimination thin independent_pairFormation unionElimination inlFormation cut hypothesis hyp_replacement equalitySymmetry hypothesisEquality inrFormation independent_isectElimination introduction extract_by_obid isectElimination instantiate universeEquality Error :inhabitedIsType,  Error :universeIsType

Latex:
\mforall{}[P1,P2,Q1,Q2:\mBbbP{}].    ((P1  =  P2)  {}\mRightarrow{}  \{uiff(Q1;Q2)\}  {}\mRightarrow{}  \{P1  \mvee{}  Q1  \mLeftarrow{}{}\mRightarrow{}  P2  \mvee{}  Q2\})

Date html generated: 2019_06_20-AM-11_17_16
Last ObjectModification: 2018_09_26-AM-10_24_44

Theory : core_2

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