Nuprl Lemma : transitive-closure-induction-ext
∀[A:Type]. ∀[P:A ⟶ ℙ]. ∀[R:A ⟶ A ⟶ ℙ].
  ((∀x,y:A.  ((x R y) 
⇒ P[x] 
⇒ P[y])) 
⇒ (∀x,y:A.  ((x TC(R) y) 
⇒ P[x] 
⇒ P[y])))
Proof
Definitions occuring in Statement : 
transitive-closure: TC(R)
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
infix_ap: x f y
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
member: t ∈ T
, 
spreadn: spread3, 
transitive-closure-induction, 
transitive-closure-minimal, 
uall: ∀[x:A]. B[x]
, 
so_lambda: so_lambda(x,y,z,w.t[x; y; z; w])
, 
so_apply: x[s1;s2;s3;s4]
, 
top: Top
, 
uimplies: b supposing a
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
Lemmas referenced : 
transitive-closure-induction, 
lifting-strict-spread, 
istype-void, 
strict4-apply, 
transitive-closure-minimal
Rules used in proof : 
introduction, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
cut, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
thin, 
sqequalHypSubstitution, 
equalityTransitivity, 
equalitySymmetry, 
isectElimination, 
baseClosed, 
Error :isect_memberEquality_alt, 
voidElimination, 
independent_isectElimination
Latex:
\mforall{}[A:Type].  \mforall{}[P:A  {}\mrightarrow{}  \mBbbP{}].  \mforall{}[R:A  {}\mrightarrow{}  A  {}\mrightarrow{}  \mBbbP{}].
    ((\mforall{}x,y:A.    ((x  R  y)  {}\mRightarrow{}  P[x]  {}\mRightarrow{}  P[y]))  {}\mRightarrow{}  (\mforall{}x,y:A.    ((x  TC(R)  y)  {}\mRightarrow{}  P[x]  {}\mRightarrow{}  P[y])))
Date html generated:
2019_06_20-PM-02_01_32
Last ObjectModification:
2019_01_11-PM-04_20_45
Theory : relations2
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