diff zf.agda @ 130:3849614bef18

new replacement axiom
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Tue, 02 Jul 2019 15:59:07 +0900
parents 0c2cbf37e002
children 327d49c2478b
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line diff
--- a/zf.agda	Tue Jul 02 09:28:26 2019 +0900
+++ b/zf.agda	Tue Jul 02 15:59:07 2019 +0900
@@ -77,7 +77,10 @@
      infinity :  ∀( X x : ZFSet  ) → x ∈ infinite →  ( x ∪ { x }) ∈ infinite 
      selection : ∀ { X : ZFSet  } →  { ψ : (x : ZFSet ) →  Set m } → ∀ {  y : ZFSet  } →  (((y : ZFSet) → y ∈ X → ψ y ) ∧ ( y ∈ X ) ) ⇔ (y ∈  Select X ψ ) 
      -- replacement : ∀ x ∀ y ∀ z ( ( ψ ( x , y ) ∧ ψ ( x , z ) ) → y = z ) → ∀ X ∃ A ∀ y ( y ∈ A ↔ ∃ x ∈ X ψ ( x , y ) )
-     replacement : {ψ : ZFSet → ZFSet} → ∀ ( X x : ZFSet  ) →  ( ψ x ∈  Replace X ψ )  
+     repl-x : {ψ : ZFSet → ZFSet} → { X x : ZFSet  }  ( lt : x ∈  Replace X ψ ) →  ZFSet
+     repl-x-∈ : {ψ : ZFSet → ZFSet} → { X x : ZFSet  } →  (lt : x ∈  Replace X ψ ) →  repl-x lt ∈ X
+     replacement← : {ψ : ZFSet → ZFSet} → ∀ ( X x : ZFSet  ) → x ∈ X → ψ x ∈  Replace X ψ 
+     replacement→ : {ψ : ZFSet → ZFSet} → ∀ ( X x : ZFSet  ) →  ( lt : x ∈  Replace X ψ ) → x ≈ ψ ( repl-x lt )  
    -- -- ∀ z [ ∀ x ( x ∈ z  → ¬ ( x ≈ ∅ ) )  ∧ ∀ x ∀ y ( x , y ∈ z ∧ ¬ ( x ≈ y )  → x ∩ y ≈ ∅  ) → ∃ u ∀ x ( x ∈ z → ∃ t ( u ∩ x) ≈ { t }) ]
    -- axiom-of-choice : Set (suc n) 
    -- axiom-of-choice = ?