Nuprl Lemma : strong-subtype-equal
∀[A,B:Type].  strong-subtype(A;B) supposing A = B ∈ Type
Proof
Definitions occuring in Statement : 
strong-subtype: strong-subtype(A;B), 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uimplies: b supposing a, 
squash: ↓T, 
prop: ℙ, 
true: True, 
subtype_rel: A ⊆r B, 
guard: {T}, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
rev_implies: P ⇐ Q, 
implies: P ⇒ Q
Lemmas referenced : 
equal_wf, 
strong-subtype_witness, 
strong-subtype-self, 
iff_weakening_equal, 
true_wf, 
squash_wf, 
strong-subtype_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
applyEquality, 
thin, 
lambdaEquality, 
sqequalHypSubstitution, 
imageElimination, 
lemma_by_obid, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
universeEquality, 
natural_numberEquality, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
because_Cache, 
instantiate, 
isect_memberEquality
Latex:
\mforall{}[A,B:Type].    strong-subtype(A;B)  supposing  A  =  B
 Date html generated: 
2016_05_13-PM-04_11_00
 Last ObjectModification: 
2016_01_14-PM-07_29_46
Theory : subtype_1
Home
Index