User talk:Drl
From The Twelf Project
Hello! I actually like the monospaced presentation better:
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You've got admin rights, btw. — Rob (and his talk) 16:02, 23 October 2006 (EDT)
Contents |
[edit] Sidebar
You might be interested in editing the sidebar. — Rob (and his talk) 16:51, 23 October 2006 (EDT)
[edit] Oh yeah
You did write one of those papers-about-twelf things, now didn't you? :-) — Rob (and his talk) 21:50, 20 March 2007 (EDT)
[edit] Aite
I'm showering, driving to school, and emailing! — Rob (and his talk) 09:18, 21 March 2007 (EDT)
[edit] Some small feature requests (didn't want to lose track of these completely)
- %reduces under a binder (comes up, e.g. in strengthening). When you know (forall x. A x < B), you could at least conclude A < B when x doesn't occur, which as I recall is enough for this example.
- new emacs mode with karl's macros
- for world violations, move some of the info that gets printed on higher chatter to the default, so it's easier to debug
[edit] Example (which Adam did much better slower than me)
tp : type. unit : tp. arrow : tp -> tp -> tp. exp : type. lam : (exp -> exp) -> exp. app : exp -> exp -> exp. of : exp -> tp -> type. of/app : of (app E1 E2) T <- of E1 (arrow T2 T) <- of E2 T2. of/lam : of (lam E) (arrow T2 T) <- {x : exp} of x T2 -> of (E x) T. false : type. %block ofb : some {T : tp} block {x : exp} {dx : of x T}. id : tp -> tp -> type. refl : id T T. lemma : ({x} {dx : of x T} of x T') -> ({x} of x T -> of x (arrow T' T0)) -> false -> type. %mode lemma +X1 +X2 -X3. %worlds (ofb) (lemma _ _ _). %total {} (lemma _ _ _). thm : of (lam [x] (app x x)) T -> false -> type. %mode thm +X1 -X2. - : thm (of/lam [x] [dx] (of/app (D x dx) (D' x dx))) XXX <- lemma D D' XXX. %worlds (ofb) (thm X Y). %total {} (thm X Y).
[edit] Any var, not just the last one
tp : type. ar : tp -> tp -> tp. %infix right 10 ar. b : tp. exp : type. app : exp -> exp -> exp. lam : (exp -> exp) -> exp. of : exp -> tp -> type. of_app : of E1 (T1 ar T2) -> of E2 T1 -> of (app E1 E2) T2. of_lam : ({x}of x T1 -> of (E x) T2) -> of (lam E) (T1 ar T2). %block ofblock : some {T:tp} block {x:exp}{u: of x T}. %worlds (ofblock) (of _ _). false : type. isvar : exp -> type. %block varBlock : some {T:tp} block {x:exp}{u: of x T}{v:isvar x}. contra : isvar X -> of X T1 -> of X (T1 ar T2) -> false -> type. %mode contra +V +D1 +D2 -E. %worlds (varBlock) (contra _ _ _ _). %total {E1 D1 D2} (contra E1 D1 D2 _). boo : isvar X -> of (app X X) T -> false -> type. %mode boo +X +D -E. boo_lam : boo X (of_app D1 D2) B <- contra X D2 D1 B. %worlds (varBlock) (boo _ _ _). %total {} (boo _ _ _).
[edit] Delphin Version by Adam
sig <tp : type> %name A t
<ar : tp -> tp -> tp> %infix right 10
;
sig <exp : type>
<app : exp -> exp -> exp>
<lam : (exp -> exp) -> exp>;
sig <of : exp -> tp -> type>
<of_app : of E1 (T1 ar T2) -> of E2 T1 -> of (app E1 E2) T2>
<of_lam : ({x}of x T1 -> of (E x) T2) -> of (lam E) (T1 ar T2)>;
sig <false : type>;
sig <eq : tp -> tp -> type> -> of X (T1 ar T2) -> false -> type.
<eqid : eq T1 T1>;
params = <exp>, <of (E#) T>;
type contextProp = <x:exp#> -> <(of x T1)> -> <(of x T2)> -> <eq T1 T2>;
fun contraEq : <eq (T1 ar T2) T1> -> <false> = fn .;
fun impossible1 : contextProp -> <of (lam [x] app x x) T> -> <false>
= fn C <of_lam ([x][d] of_app (D1 x d) (D2 x d))> =>
(case {<x>}{<d:of x T1>} contraEq ((C with <x> <d> <d> => <eqid>) <x> <D1 x d> <D2 x d>)
of {<x>}{<d>}<bot> => <bot>);
d
fun impossibleGeneral : contextProp -> <x:exp#> -> <of (app x x) T> -> <false>
= fn C <x> <of_app D1 D2> => contraEq (C <x> <D1> <D2>);
</code>
