Metamath Proof Explorer


Theorem cofcutr2d

Description: If X is the cut of A and B , then B is coinitial with ( _RightX ) . Second half of theorem 2.9 of Gonshor p. 12. (Contributed by Scott Fenton, 25-Sep-2024)

Ref Expression
Hypotheses cofcutrd.1 φAsB
cofcutrd.2 φX=A|sB
Assertion cofcutr2d Could not format assertion : No typesetting found for |- ( ph -> A. z e. ( _Right ` X ) E. w e. B w <_s z ) with typecode |-

Proof

Step Hyp Ref Expression
1 cofcutrd.1 φAsB
2 cofcutrd.2 φX=A|sB
3 cofcutr Could not format ( ( A < ( A. x e. ( _Left ` X ) E. y e. A x <_s y /\ A. z e. ( _Right ` X ) E. w e. B w <_s z ) ) : No typesetting found for |- ( ( A < ( A. x e. ( _Left ` X ) E. y e. A x <_s y /\ A. z e. ( _Right ` X ) E. w e. B w <_s z ) ) with typecode |-
4 1 2 3 syl2anc Could not format ( ph -> ( A. x e. ( _Left ` X ) E. y e. A x <_s y /\ A. z e. ( _Right ` X ) E. w e. B w <_s z ) ) : No typesetting found for |- ( ph -> ( A. x e. ( _Left ` X ) E. y e. A x <_s y /\ A. z e. ( _Right ` X ) E. w e. B w <_s z ) ) with typecode |-
5 4 simprd Could not format ( ph -> A. z e. ( _Right ` X ) E. w e. B w <_s z ) : No typesetting found for |- ( ph -> A. z e. ( _Right ` X ) E. w e. B w <_s z ) with typecode |-