Zulip Chat Archive
Stream: new members
Topic: inequality following from an equality
Andre Popovitch (Jan 20 2022 at 01:41):
If in my goal view I have
eq : succ h + 0 = a
is there a way to create
eq : succ h >= a
?
Johan Commelin (Jan 20 2022 at 01:44):
Does have foo : succ h ≥ a, by library_search
help?
Andre Popovitch (Jan 20 2022 at 01:44):
I'm playing the game haha. I get unknown identifier 'library_search'
Andre Popovitch (Jan 20 2022 at 01:45):
But if I can create ∃ (c, succ h + c = a)
, which I think I ought to be able to with c = 0
, I think that would be sufficient
Patrick Johnson (Jan 20 2022 at 02:26):
replace eq : succ h ≥ a := ge_of_eq eq
Andre Popovitch (Jan 20 2022 at 02:28):
That works, thanks! Is there a way to create the existential directly?
Patrick Johnson (Jan 20 2022 at 02:30):
have h : ∃ c, succ h + c = a := ⟨0, eq⟩
or
have h : succ h ≥ a := ⟨0, eq⟩
Andre Popovitch (Jan 20 2022 at 02:39):
woah, thank you
Andre Popovitch (Jan 20 2022 at 02:39):
oh, so an ∃ is just a tuple where the type of the second element can depend on the value of the first element?
Last updated: Dec 20 2023 at 11:08 UTC