Nuprl Lemma : inv_image_ind
∀[A:Type]. ∀[r:A ⟶ A ⟶ ℙ]. ∀[B:Type].  ∀f:B ⟶ A. (WellFnd{i}(A;x,y.r[x;y]) 
⇒ WellFnd{i}(B;x,y.r[f x;f y]))
Proof
Definitions occuring in Statement : 
wellfounded: WellFnd{i}(A;x,y.R[x; y])
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
Lemmas referenced : 
inv_image_ind_tp
Rules used in proof : 
lemma_by_obid
Latex:
\mforall{}[A:Type].  \mforall{}[r:A  {}\mrightarrow{}  A  {}\mrightarrow{}  \mBbbP{}].  \mforall{}[B:Type].
    \mforall{}f:B  {}\mrightarrow{}  A.  (WellFnd\{i\}(A;x,y.r[x;y])  {}\mRightarrow{}  WellFnd\{i\}(B;x,y.r[f  x;f  y]))
Date html generated:
2016_05_13-PM-03_18_25
Last ObjectModification:
2015_12_26-AM-09_06_48
Theory : well_fnd
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