Nuprl Lemma : half-squash-stable__and
∀[P,Q:ℙ].  (half-squash-stable(P) 
⇒ half-squash-stable(Q) 
⇒ half-squash-stable(P ∧ Q))
Proof
Definitions occuring in Statement : 
half-squash-stable: half-squash-stable(P)
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
Definitions unfolded in proof : 
guard: {T}
, 
uimplies: b supposing a
, 
so_apply: x[s1;s2]
, 
so_lambda: λ2x y.t[x; y]
, 
prop: ℙ
, 
member: t ∈ T
, 
cand: A c∧ B
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
uall: ∀[x:A]. B[x]
, 
half-squash-stable: half-squash-stable(P)
Lemmas referenced : 
implies-quotient-true, 
equiv_rel_true, 
true_wf, 
quotient_wf
Rules used in proof : 
promote_hyp, 
independent_functionElimination, 
productElimination, 
universeEquality, 
functionEquality, 
independent_isectElimination, 
because_Cache, 
lambdaEquality, 
hypothesisEquality, 
cumulativity, 
productEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
hypothesis, 
independent_pairFormation, 
cut, 
lambdaFormation, 
isect_memberFormation, 
computationStep, 
sqequalTransitivity, 
sqequalReflexivity, 
sqequalRule, 
sqequalSubstitution
Latex:
\mforall{}[P,Q:\mBbbP{}].    (half-squash-stable(P)  {}\mRightarrow{}  half-squash-stable(Q)  {}\mRightarrow{}  half-squash-stable(P  \mwedge{}  Q))
Date html generated:
2017_09_29-PM-05_48_10
Last ObjectModification:
2017_08_30-AM-11_07_04
Theory : quot_1
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