X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground_2%2Flib%2Fstreams.ma;h=4bb3883cebdadf3b4ef3f4b113be6fa506caab06;hb=4b8544042a6f3c5f5d303d4120c69abbc34ce15b;hp=30a045c542de130dabf94c131524cc3f29329166;hpb=7d8ebeb7b6f21204b88786c738c67f52f3703c5b;p=helm.git diff --git a/matita/matita/contribs/lambdadelta/ground_2/lib/streams.ma b/matita/matita/contribs/lambdadelta/ground_2/lib/streams.ma index 30a045c54..4bb3883ce 100644 --- a/matita/matita/contribs/lambdadelta/ground_2/lib/streams.ma +++ b/matita/matita/contribs/lambdadelta/ground_2/lib/streams.ma @@ -25,17 +25,17 @@ coinductive stream (A:Type[0]): Type[0] ≝ interpretation "cons (nstream)" 'Cons b t = (seq ? b t). coinductive eq_stream (A): relation (stream A) ≝ -| eq_sec: ∀t1,t2,b1,b2. b1 = b2 → eq_stream A t1 t2 → eq_stream A (b1@t1) (b2@t2) +| eq_seq: ∀t1,t2,b1,b2. b1 = b2 → eq_stream A t1 t2 → eq_stream A (b1@t1) (b2@t2) . interpretation "extensional equivalence (nstream)" 'ExtEq A t1 t2 = (eq_stream A t1 t2). -definition eq_stream_repl_back (A) (R:predicate …) (t1,t2) ≝ - t1 ≐⦋A⦌ t2 → R t1 → R t2. +definition eq_stream_repl_back (A) (R:predicate …) ≝ + ∀t1,t2. t1 ≐⦋A⦌ t2 → R t1 → R t2. -definition eq_stream_repl_fwd (A) (R:predicate …) (t1,t2) ≝ - t2 ≐⦋A⦌ t1 → R t1 → R t2. +definition eq_stream_repl_fwd (A) (R:predicate …) ≝ + ∀t1,t2. t2 ≐⦋A⦌ t1 → R t1 → R t2. (* Basic inversion lemmas ***************************************************) @@ -56,27 +56,27 @@ lemma stream_expand (A) (t:stream A): t = match t with [ seq a u ⇒ a @ u ]. qed. let corec eq_stream_refl: ∀A. reflexive … (eq_stream A) ≝ ?. -#A * #b #t @eq_sec // +#A * #b #t @eq_seq // qed. let corec eq_stream_sym: ∀A. symmetric … (eq_stream A) ≝ ?. #A #t1 #t2 * -t1 -t2 -#t1 #t2 #b1 #b2 #Hb #Ht @eq_sec /2 width=1 by/ +#t1 #t2 #b1 #b2 #Hb #Ht @eq_seq /2 width=1 by/ qed-. -lemma eq_stream_repl_sym: ∀A,R,t1,t2. eq_stream_repl_back A R t1 t2 → eq_stream_repl_fwd A R t1 t2. -/3 width=1 by eq_stream_sym/ qed-. +lemma eq_stream_repl_sym: ∀A,R. eq_stream_repl_back A R → eq_stream_repl_fwd A R. +/3 width=3 by eq_stream_sym/ qed-. (* Main properties **********************************************************) let corec eq_stream_trans: ∀A. Transitive … (eq_stream A) ≝ ?. #A #t1 #t * -t1 -t #t1 #t #b1 #b #Hb1 #Ht1 * #b2 #t2 #H cases (eq_stream_inv_seq A … H) -H -#Hb2 #Ht2 @eq_sec /2 width=3 by/ +#Hb2 #Ht2 @eq_seq /2 width=3 by/ qed-. theorem eq_stream_canc_sn: ∀A,t,t1,t2. t ≐ t1 → t ≐ t2 → t1 ≐⦋A⦌ t2. -/3 width=4 by eq_stream_trans, eq_stream_repl_sym/ qed-. +/3 width=3 by eq_stream_trans, eq_stream_sym/ qed-. theorem eq_stream_canc_dx: ∀A,t,t1,t2. t1 ≐ t → t2 ≐ t → t1 ≐⦋A⦌ t2. -/3 width=4 by eq_stream_trans, eq_stream_repl_sym/ qed-. +/3 width=3 by eq_stream_trans, eq_stream_sym/ qed-.