X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground_2%2Flib%2Fstreams_eq.ma;h=878185ca18e89c24048ea6f0e8ce29fc58ab321b;hb=a77d0bd6a04e94f765d329d47b37d9e04d349b14;hp=839811603e97da52ff2d9fd5b8a138ac62f13303;hpb=859c5cbb8ebffeddd1dd9cbc462e046b0709b4e4;p=helm.git diff --git a/matita/matita/contribs/lambdadelta/ground_2/lib/streams_eq.ma b/matita/matita/contribs/lambdadelta/ground_2/lib/streams_eq.ma index 839811603..878185ca1 100644 --- a/matita/matita/contribs/lambdadelta/ground_2/lib/streams_eq.ma +++ b/matita/matita/contribs/lambdadelta/ground_2/lib/streams_eq.ma @@ -12,43 +12,43 @@ (* *) (**************************************************************************) -include "ground_2/notation/relations/exteq_3.ma". +include "ground_2/notation/relations/ringeq_3.ma". include "ground_2/lib/streams.ma". (* STREAMS ******************************************************************) coinductive eq_stream (A): relation (stream A) ≝ -| eq_seq: ∀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). + 'RingEq A t1 t2 = (eq_stream A t1 t2). definition eq_stream_repl (A) (R:relation …) ≝ - ∀t1,t2. t1 ≐⦋A⦌ t2 → R t1 t2. + ∀t1,t2. t1 ≗{A} t2 → R t1 t2. definition eq_stream_repl_back (A) (R:predicate …) ≝ - ∀t1. R t1 → ∀t2. t1 ≐⦋A⦌ t2 → R t2. + ∀t1. R t1 → ∀t2. t1 ≗{A} t2 → R t2. definition eq_stream_repl_fwd (A) (R:predicate …) ≝ - ∀t1. R t1 → ∀t2. t2 ≐⦋A⦌ t1 → R t2. + ∀t1. R t1 → ∀t2. t2 ≗{A} t1 → R t2. (* Basic inversion lemmas ***************************************************) -lemma eq_stream_inv_seq: ∀A,t1,t2. t1 ≐⦋A⦌ t2 → - ∀u1,u2,a1,a2. a1@u1 = t1 → a2@u2 = t2 → - u1 ≐ u2 ∧ a1 = a2. +lemma eq_stream_inv_seq: ∀A,t1,t2. t1 ≗{A} t2 → + ∀u1,u2,a1,a2. a1⨮u1 = t1 → a2⨮u2 = t2 → + u1 ≗ u2 ∧ a1 = a2. #A #t1 #t2 * -t1 -t2 #t1 #t2 #b1 #b2 #Hb #Ht #u1 #u2 #a1 #a2 #H1 #H2 destruct /2 width=1 by conj/ qed-. (* Basic properties *********************************************************) -let corec eq_stream_refl: ∀A. reflexive … (eq_stream A) ≝ ?. +corec lemma eq_stream_refl: ∀A. reflexive … (eq_stream A). #A * #b #t @eq_seq // qed. -let corec eq_stream_sym: ∀A. symmetric … (eq_stream A) ≝ ?. +corec lemma eq_stream_sym: ∀A. symmetric … (eq_stream A). #A #t1 #t2 * -t1 -t2 #t1 #t2 #b1 #b2 #Hb #Ht @eq_seq /2 width=1 by/ qed-. @@ -58,14 +58,14 @@ lemma eq_stream_repl_sym: ∀A,R. eq_stream_repl_back A R → eq_stream_repl_fwd (* Main properties **********************************************************) -let corec eq_stream_trans: ∀A. Transitive … (eq_stream A) ≝ ?. +corec theorem eq_stream_trans: ∀A. Transitive … (eq_stream A). #A #t1 #t * -t1 -t #t1 #t #b1 #b * #Ht1 * #b2 #t2 #H cases (eq_stream_inv_seq A … H) -H -b /3 width=7 by eq_seq/ qed-. -theorem eq_stream_canc_sn: ∀A,t,t1,t2. t ≐ t1 → t ≐ t2 → t1 ≐⦋A⦌ t2. +theorem eq_stream_canc_sn: ∀A,t,t1,t2. t ≗ t1 → t ≗ t2 → t1 ≗{A} t2. /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. +theorem eq_stream_canc_dx: ∀A,t,t1,t2. t1 ≗ t → t2 ≗ t → t1 ≗{A} t2. /3 width=3 by eq_stream_trans, eq_stream_sym/ qed-.