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: so_apply: x[s1;s2] all: x:A. B[x] implies:  Q apply: 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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