- | ∃∃f. i < d & f1 ▭ i ≘ f & f2 = ❨d-i,h❩;f.
-#g1 #f2 #d #h #i @(insert_eq_1 … (❨d,h❩;g1))
+ | ∃∃f. i < d & f1 ▭ i ≘ f & f2 = ❨d-i,h❩◗f.
+#g1 #f2 #d #h #i @(insert_eq_1 … (❨d,h❩◗g1))
- ❨d, h❩;f1 ▭ i ≘ f2 → i < d →
- ∃∃f. f1 ▭ i ≘ f & f2 = ❨d-i,h❩;f.
+ ❨d, h❩◗f1 ▭ i ≘ f2 → i < d →
+ ∃∃f. f1 ▭ i ≘ f & f2 = ❨d-i,h❩◗f.
#f1 #f2 #d #h #i #H elim (fr2_minus_inv_lcons_sn … H) -H *
[ #Hdi #_ #Hid elim (nlt_ge_false … Hid Hdi)
| /2 width=3 by ex2_intro/
#f1 #f2 #d #h #i #H elim (fr2_minus_inv_lcons_sn … H) -H *
[ #Hdi #_ #Hid elim (nlt_ge_false … Hid Hdi)
| /2 width=3 by ex2_intro/