∀C:half_ordered_set.∀s:segment C.∀a:sequence (half_segment_ordered_set C s).
∀x,h. uparrow C ⌊n,\fst (a n)⌋ x → uparrow (half_segment_ordered_set C s) a ≪x,h≫.
intros; cases H (Ha Hx); split;
-[ intro n; intro H; apply (Ha n); apply (sx2x ???? H);
+[ intro n; intro H; apply (Ha n); apply rule H;
| cases Hx; split;
- [ intro n; intro H; apply (H1 n);apply (sx2x ???? H);
- | intros; cases (H2 (\fst y)); [2: apply (sx2x ???? H3);]
- exists [apply w] apply (x2sx ?? (a w) y H4);]]
+ [ intro n; intro H; apply (H1 n);apply rule H;
+ | intros; cases (H2 (\fst y)); [2: apply rule H3;]
+ exists [apply w] apply (x2sx_ ?? (a w) y H4);]]
qed.
notation "'segment_preserves_uparrow'" non associative with precedence 90 for @{'segment_preserves_uparrow}.