X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground_2%2Frelocation%2Frtmap_coafter.ma;h=0eb098301ceca87f2f6a1daf1b8705e3eb2139b7;hp=5b0e3c1e9e1872e08c631e5758887140013c8911;hb=bd53c4e895203eb049e75434f638f26b5a161a2b;hpb=3b7b8afcb429a60d716d5226a5b6ab0d003228b1

diff --git a/matita/matita/contribs/lambdadelta/ground_2/relocation/rtmap_coafter.ma b/matita/matita/contribs/lambdadelta/ground_2/relocation/rtmap_coafter.ma
index 5b0e3c1e9..0eb098301 100644
--- a/matita/matita/contribs/lambdadelta/ground_2/relocation/rtmap_coafter.ma
+++ b/matita/matita/contribs/lambdadelta/ground_2/relocation/rtmap_coafter.ma
@@ -31,14 +31,14 @@ interpretation "relational co-composition (rtmap)"
    'RCoAfter f1 f2 f = (coafter f1 f2 f).
 
 definition H_coafter_inj: predicate rtmap ≝
-                          λf1. 𝐓⦃f1⦄ →
+                          λf1. 𝐓❪f1❫ →
                           ∀f,f21,f22. f1 ~⊚ f21 ≘ f → f1 ~⊚ f22 ≘ f → f21 ≡ f22.
 
 definition H_coafter_fwd_isid2: predicate rtmap ≝
-                                λf1. ∀f2,f. f1 ~⊚ f2 ≘ f → 𝐓⦃f1⦄ → 𝐈⦃f⦄ → 𝐈⦃f2⦄.
+                                λf1. ∀f2,f. f1 ~⊚ f2 ≘ f → 𝐓❪f1❫ → 𝐈❪f❫ → 𝐈❪f2❫.
 
 definition H_coafter_isfin2_fwd: predicate rtmap ≝
-                                 λf1. ∀f2. 𝐅⦃f2⦄ → 𝐓⦃f1⦄ → ∀f. f1 ~⊚ f2 ≘ f →  𝐅⦃f⦄.
+                                 λf1. ∀f2. 𝐅❪f2❫ → 𝐓❪f1❫ → ∀f. f1 ~⊚ f2 ≘ f →  𝐅❪f❫.
 
 (* Basic inversion lemmas ***************************************************)
 
@@ -238,7 +238,7 @@ lemma coafter_mono_eq: ∀f1,f2,f. f1 ~⊚ f2 ≘ f → ∀g1,g2,g. g1 ~⊚ g2 
 
 (* Forward lemmas with pushs ************************************************)
 
-lemma coafter_fwd_pushs: ∀j,i,g2,f1,g. g2 ~⊚ ⫯*[i]f1 ≘ g → @⦃i, g2⦄ ≘ j →
+lemma coafter_fwd_pushs: ∀j,i,g2,f1,g. g2 ~⊚ ⫯*[i]f1 ≘ g → @❪i, g2❫ ≘ j →
                          ∃f. ⫯*[j] f = g.
 #j elim j -j
 [ #i #g2 #f1 #g #Hg #H
@@ -278,7 +278,7 @@ qed-.
 
 (* Properties with iterated tail ********************************************)
 
-lemma coafter_tls: ∀j,i,f1,f2,f. @⦃i, f1⦄ ≘ j →
+lemma coafter_tls: ∀j,i,f1,f2,f. @❪i, f1❫ ≘ j →
                    f1 ~⊚ f2 ≘ f → ⫱*[j]f1 ~⊚ ⫱*[i]f2 ≘ ⫱*[j]f.
 #j elim j -j [ #i | #j #IH * [| #i ] ] #f1 #f2 #f #Hf1 #Hf
 [ elim (at_inv_xxp … Hf1) -Hf1 [ |*: // ] #g1 #Hg1 #H1 destruct //
@@ -294,12 +294,12 @@ lemma coafter_tls: ∀j,i,f1,f2,f. @⦃i, f1⦄ ≘ j →
 ]
 qed.
 
-lemma coafter_tls_O: ∀n,f1,f2,f. @⦃0, f1⦄ ≘ n →
+lemma coafter_tls_O: ∀n,f1,f2,f. @❪0, f1❫ ≘ n →
                      f1 ~⊚ f2 ≘ f → ⫱*[n]f1 ~⊚ f2 ≘ ⫱*[n]f.
 /2 width=1 by coafter_tls/ qed.
 
 lemma coafter_tls_succ: ∀g2,g1,g. g2 ~⊚ g1 ≘ g →
-                        ∀n. @⦃0, g2⦄ ≘ n → ⫱*[↑n]g2 ~⊚ ⫱g1 ≘ ⫱*[↑n]g.
+                        ∀n. @❪0, g2❫ ≘ n → ⫱*[↑n]g2 ~⊚ ⫱g1 ≘ ⫱*[↑n]g.
 #g2 #g1 #g #Hg #n #Hg2
 lapply (coafter_tls … Hg2 … Hg) -Hg #Hg
 lapply (at_pxx_tls … Hg2) -Hg2 #H
@@ -308,7 +308,7 @@ elim (coafter_inv_pxx … Hg … H2) -Hg * #f1 #f #Hf #H1 #H0 destruct
 <tls_S <tls_S <H2 <H0 -g2 -g -n //
 qed.
 
-lemma coafter_fwd_xpx_pushs: ∀g2,f1,g,i,j. @⦃i, g2⦄ ≘ j → g2 ~⊚ ⫯*[↑i]f1 ≘ g →
+lemma coafter_fwd_xpx_pushs: ∀g2,f1,g,i,j. @❪i, g2❫ ≘ j → g2 ~⊚ ⫯*[↑i]f1 ≘ g →
                              ∃∃f.  ⫱*[↑j]g2 ~⊚ f1 ≘ f & ⫯*[↑j]f = g.
 #g2 #g1 #g #i #j #Hg2 <pushs_xn #Hg
 elim (coafter_fwd_pushs … Hg Hg2) #f #H0 destruct
@@ -319,7 +319,7 @@ elim (coafter_inv_ppx … Hf) [|*: // ] -Hf #g #Hg #H destruct
 /2 width=3 by ex2_intro/
 qed-.
 
-lemma coafter_fwd_xnx_pushs: ∀g2,f1,g,i,j. @⦃i, g2⦄ ≘ j → g2 ~⊚ ⫯*[i]↑f1 ≘ g →
+lemma coafter_fwd_xnx_pushs: ∀g2,f1,g,i,j. @❪i, g2❫ ≘ j → g2 ~⊚ ⫯*[i]↑f1 ≘ g →
                              ∃∃f. ⫱*[↑j]g2 ~⊚ f1 ≘ f & ⫯*[j] ↑f = g.
 #g2 #g1 #g #i #j #Hg2 #Hg
 elim (coafter_fwd_pushs … Hg Hg2) #f #H0 destruct
@@ -332,12 +332,12 @@ qed-.
 
 (* Properties with test for identity ****************************************)
 
-corec lemma coafter_isid_sn: ∀f1. 𝐈⦃f1⦄ → ∀f2. f1 ~⊚ f2 ≘ f2.
+corec lemma coafter_isid_sn: ∀f1. 𝐈❪f1❫ → ∀f2. f1 ~⊚ f2 ≘ f2.
 #f1 * -f1 #f1 #g1 #Hf1 #H1 #f2 cases (pn_split f2) * #g2 #H2
 /3 width=7 by coafter_push, coafter_refl/
 qed.
 
-corec lemma coafter_isid_dx: ∀f2,f. 𝐈⦃f2⦄ → 𝐈⦃f⦄ → ∀f1. f1 ~⊚ f2 ≘ f.
+corec lemma coafter_isid_dx: ∀f2,f. 𝐈❪f2❫ → 𝐈❪f❫ → ∀f1. f1 ~⊚ f2 ≘ f.
 #f2 #f * -f2 #f2 #g2 #Hf2 #H2 * -f #f #g #Hf #H #f1 cases (pn_split f1) * #g1 #H1
 [ /3 width=7 by coafter_refl/
 | @(coafter_next … H1 … H) /3 width=3 by isid_push/
@@ -346,27 +346,27 @@ qed.
 
 (* Inversion lemmas with test for identity **********************************)
 
-lemma coafter_isid_inv_sn: ∀f1,f2,f. f1 ~⊚ f2 ≘ f → 𝐈⦃f1⦄ → f2 ≡ f.
+lemma coafter_isid_inv_sn: ∀f1,f2,f. f1 ~⊚ f2 ≘ f → 𝐈❪f1❫ → f2 ≡ f.
 /3 width=6 by coafter_isid_sn, coafter_mono/ qed-.
 
-lemma coafter_isid_inv_dx: ∀f1,f2,f. f1 ~⊚ f2 ≘ f → 𝐈⦃f2⦄ → 𝐈⦃f⦄.
+lemma coafter_isid_inv_dx: ∀f1,f2,f. f1 ~⊚ f2 ≘ f → 𝐈❪f2❫ → 𝐈❪f❫.
 /4 width=4 by eq_id_isid, coafter_isid_dx, coafter_mono/ qed-.
 
 (* Properties with test for uniform relocations *****************************)
 
-lemma coafter_isuni_isid: ∀f2. 𝐈⦃f2⦄ → ∀f1. 𝐔⦃f1⦄ → f1 ~⊚ f2 ≘ f2.
+lemma coafter_isuni_isid: ∀f2. 𝐈❪f2❫ → ∀f1. 𝐔❪f1❫ → f1 ~⊚ f2 ≘ f2.
 #f #Hf #g #H elim H -g
 /3 width=5 by coafter_isid_sn, coafter_eq_repl_back0, coafter_next, eq_push_inv_isid/
 qed.
 
 
 (*
-lemma coafter_isid_isuni: ∀f1,f2. 𝐈⦃f2⦄ → 𝐔⦃f1⦄ → f1 ~⊚ ↑f2 ≘ ↑f1.
+lemma coafter_isid_isuni: ∀f1,f2. 𝐈❪f2❫ → 𝐔❪f1❫ → f1 ~⊚ ↑f2 ≘ ↑f1.
 #f1 #f2 #Hf2 #H elim H -H
 /5 width=7 by coafter_isid_dx, coafter_eq_repl_back2, coafter_next, coafter_push, eq_push_inv_isid/
 qed.
 
-lemma coafter_uni_next2: ∀f2. 𝐔⦃f2⦄ → ∀f1,f. ↑f2 ~⊚ f1 ≘ f → f2 ~⊚ ↑f1 ≘ f.
+lemma coafter_uni_next2: ∀f2. 𝐔❪f2❫ → ∀f1,f. ↑f2 ~⊚ f1 ≘ f → f2 ~⊚ ↑f1 ≘ f.
 #f2 #H elim H -f2
 [ #f2 #Hf2 #f1 #f #Hf
   elim (coafter_inv_nxx … Hf) -Hf [2,3: // ] #g #Hg #H0 destruct
@@ -380,20 +380,20 @@ qed.
 
 (* Properties with uniform relocations **************************************)
 
-lemma coafter_uni_sn: ∀i,f. 𝐔❴i❵ ~⊚ f ≘ ⫯*[i] f.
+lemma coafter_uni_sn: ∀i,f. 𝐔❨i❩ ~⊚ f ≘ ⫯*[i] f.
 #i elim i -i /2 width=5 by coafter_isid_sn, coafter_next/
 qed.
 
 (*
-lemma coafter_uni: ∀n1,n2. 𝐔❴n1❵ ~⊚ 𝐔❴n2❵ ≘ 𝐔❴n1+n2❵.
+lemma coafter_uni: ∀n1,n2. 𝐔❨n1❩ ~⊚ 𝐔❨n2❩ ≘ 𝐔❨n1+n2❩.
 @nat_elim2
 /4 width=5 by coafter_uni_next2, coafter_isid_sn, coafter_isid_dx, coafter_next/
 qed.
 
 (* Forward lemmas on at *****************************************************)
 
-lemma coafter_at_fwd: ∀i,i1,f. @⦃i1, f⦄ ≘ i → ∀f2,f1. f2 ~⊚ f1 ≘ f →
-                      ∃∃i2. @⦃i1, f1⦄ ≘ i2 & @⦃i2, f2⦄ ≘ i.
+lemma coafter_at_fwd: ∀i,i1,f. @❪i1, f❫ ≘ i → ∀f2,f1. f2 ~⊚ f1 ≘ f →
+                      ∃∃i2. @❪i1, f1❫ ≘ i2 & @❪i2, f2❫ ≘ i.
 #i elim i -i [2: #i #IH ] #i1 #f #Hf #f2 #f1 #Hf21
 [ elim (at_inv_xxn … Hf) -Hf [1,3:* |*: // ]
   [1: #g #j1 #Hg #H0 #H |2,4: #g #Hg #H ]
@@ -409,8 +409,8 @@ lemma coafter_at_fwd: ∀i,i1,f. @⦃i1, f⦄ ≘ i → ∀f2,f1. f2 ~⊚ f1 ≘
 /3 width=9 by at_refl, at_push, at_next, ex2_intro/
 qed-.
 
-lemma coafter_fwd_at: ∀i,i2,i1,f1,f2. @⦃i1, f1⦄ ≘ i2 → @⦃i2, f2⦄ ≘ i →
-                      ∀f. f2 ~⊚ f1 ≘ f → @⦃i1, f⦄ ≘ i.
+lemma coafter_fwd_at: ∀i,i2,i1,f1,f2. @❪i1, f1❫ ≘ i2 → @❪i2, f2❫ ≘ i →
+                      ∀f. f2 ~⊚ f1 ≘ f → @❪i1, f❫ ≘ i.
 #i elim i -i [2: #i #IH ] #i2 #i1 #f1 #f2 #Hf1 #Hf2 #f #Hf
 [ elim (at_inv_xxn … Hf2) -Hf2 [1,3: * |*: // ]
   #g2 [ #j2 ] #Hg2 [ #H22 ] #H20
@@ -427,14 +427,14 @@ lemma coafter_fwd_at: ∀i,i2,i1,f1,f2. @⦃i1, f1⦄ ≘ i2 → @⦃i2, f2⦄ 
 ]
 qed-.
 
-lemma coafter_fwd_at2: ∀f,i1,i. @⦃i1, f⦄ ≘ i → ∀f1,i2. @⦃i1, f1⦄ ≘ i2 →
-                       ∀f2. f2 ~⊚ f1 ≘ f → @⦃i2, f2⦄ ≘ i.
+lemma coafter_fwd_at2: ∀f,i1,i. @❪i1, f❫ ≘ i → ∀f1,i2. @❪i1, f1❫ ≘ i2 →
+                       ∀f2. f2 ~⊚ f1 ≘ f → @❪i2, f2❫ ≘ i.
 #f #i1 #i #Hf #f1 #i2 #Hf1 #f2 #H elim (coafter_at_fwd … Hf … H) -f
 #j1 #H #Hf2 <(at_mono … Hf1 … H) -i1 -i2 //
 qed-.
 
-lemma coafter_fwd_at1: ∀i,i2,i1,f,f2. @⦃i1, f⦄ ≘ i → @⦃i2, f2⦄ ≘ i →
-                       ∀f1. f2 ~⊚ f1 ≘ f → @⦃i1, f1⦄ ≘ i2.
+lemma coafter_fwd_at1: ∀i,i2,i1,f,f2. @❪i1, f❫ ≘ i → @❪i2, f2❫ ≘ i →
+                       ∀f1. f2 ~⊚ f1 ≘ f → @❪i1, f1❫ ≘ i2.
 #i elim i -i [2: #i #IH ] #i2 #i1 #f #f2 #Hf #Hf2 #f1 #Hf1
 [ elim (at_inv_xxn … Hf) -Hf [1,3: * |*: // ]
   #g [ #j1 ] #Hg [ #H01 ] #H00
@@ -453,8 +453,8 @@ qed-.
 
 (* Properties with at *******************************************************)
 
-lemma coafter_uni_dx: ∀i2,i1,f2. @⦃i1, f2⦄ ≘ i2 →
-                      ∀f. f2 ~⊚ 𝐔❴i1❵ ≘ f → 𝐔❴i2❵ ~⊚ ⫱*[i2] f2 ≘ f.
+lemma coafter_uni_dx: ∀i2,i1,f2. @❪i1, f2❫ ≘ i2 →
+                      ∀f. f2 ~⊚ 𝐔❨i1❩ ≘ f → 𝐔❨i2❩ ~⊚ ⫱*[i2] f2 ≘ f.
 #i2 elim i2 -i2
 [ #i1 #f2 #Hf2 #f #Hf
   elim (at_inv_xxp … Hf2) -Hf2 // #g2 #H1 #H2 destruct
@@ -472,8 +472,8 @@ lemma coafter_uni_dx: ∀i2,i1,f2. @⦃i1, f2⦄ ≘ i2 →
 ]
 qed.
 
-lemma coafter_uni_sn: ∀i2,i1,f2. @⦃i1, f2⦄ ≘ i2 →
-                      ∀f. 𝐔❴i2❵ ~⊚ ⫱*[i2] f2 ≘ f → f2 ~⊚ 𝐔❴i1❵ ≘ f.
+lemma coafter_uni_sn: ∀i2,i1,f2. @❪i1, f2❫ ≘ i2 →
+                      ∀f. 𝐔❨i2❩ ~⊚ ⫱*[i2] f2 ≘ f → f2 ~⊚ 𝐔❨i1❩ ≘ f.
 #i2 elim i2 -i2
 [ #i1 #f2 #Hf2 #f #Hf
   elim (at_inv_xxp … Hf2) -Hf2 // #g2 #H1 #H2 destruct
@@ -488,8 +488,8 @@ lemma coafter_uni_sn: ∀i2,i1,f2. @⦃i1, f2⦄ ≘ i2 →
 ]
 qed-.
 
-lemma coafter_uni_succ_dx: ∀i2,i1,f2. @⦃i1, f2⦄ ≘ i2 →
-                           ∀f. f2 ~⊚ 𝐔❴↑i1❵ ≘ f → 𝐔❴↑i2❵ ~⊚ ⫱*[↑i2] f2 ≘ f.
+lemma coafter_uni_succ_dx: ∀i2,i1,f2. @❪i1, f2❫ ≘ i2 →
+                           ∀f. f2 ~⊚ 𝐔❨↑i1❩ ≘ f → 𝐔❨↑i2❩ ~⊚ ⫱*[↑i2] f2 ≘ f.
 #i2 elim i2 -i2
 [ #i1 #f2 #Hf2 #f #Hf
   elim (at_inv_xxp … Hf2) -Hf2 // #g2 #H1 #H2 destruct
@@ -508,8 +508,8 @@ lemma coafter_uni_succ_dx: ∀i2,i1,f2. @⦃i1, f2⦄ ≘ i2 →
 ]
 qed.
 
-lemma coafter_uni_succ_sn: ∀i2,i1,f2. @⦃i1, f2⦄ ≘ i2 →
-                           ∀f. 𝐔❴↑i2❵ ~⊚ ⫱*[↑i2] f2 ≘ f → f2 ~⊚ 𝐔❴↑i1❵ ≘ f.
+lemma coafter_uni_succ_sn: ∀i2,i1,f2. @❪i1, f2❫ ≘ i2 →
+                           ∀f. 𝐔❨↑i2❩ ~⊚ ⫱*[↑i2] f2 ≘ f → f2 ~⊚ 𝐔❨↑i1❩ ≘ f.
 #i2 elim i2 -i2
 [ #i1 #f2 #Hf2 #f #Hf
   elim (at_inv_xxp … Hf2) -Hf2 // #g2 #H1 #H2 destruct
@@ -525,43 +525,43 @@ lemma coafter_uni_succ_sn: ∀i2,i1,f2. @⦃i1, f2⦄ ≘ i2 →
 ]
 qed-.
 
-lemma coafter_uni_one_dx: ∀f2,f. ⫯f2 ~⊚ 𝐔❴↑O❵ ≘ f → 𝐔❴↑O❵ ~⊚ f2 ≘ f.
+lemma coafter_uni_one_dx: ∀f2,f. ⫯f2 ~⊚ 𝐔❨↑O❩ ≘ f → 𝐔❨↑O❩ ~⊚ f2 ≘ f.
 #f2 #f #H @(coafter_uni_succ_dx … (⫯f2)) /2 width=3 by at_refl/
 qed.
 
-lemma coafter_uni_one_sn: ∀f1,f. 𝐔❴↑O❵ ~⊚ f1 ≘ f → ⫯f1 ~⊚ 𝐔❴↑O❵ ≘ f.
+lemma coafter_uni_one_sn: ∀f1,f. 𝐔❨↑O❩ ~⊚ f1 ≘ f → ⫯f1 ~⊚ 𝐔❨↑O❩ ≘ f.
 /3 width=3 by coafter_uni_succ_sn, at_refl/ qed-.
 *)
 (* Forward lemmas with istot ************************************************)
 (*
-lemma coafter_istot_fwd: ∀f2,f1,f. f2 ~⊚ f1 ≘ f → 𝐓⦃f2⦄ → 𝐓⦃f1⦄ → 𝐓⦃f⦄.
+lemma coafter_istot_fwd: ∀f2,f1,f. f2 ~⊚ f1 ≘ f → 𝐓❪f2❫ → 𝐓❪f1❫ → 𝐓❪f❫.
 #f2 #f1 #f #Hf #Hf2 #Hf1 #i1 elim (Hf1 i1) -Hf1
 #i2 #Hf1 elim (Hf2 i2) -Hf2
 /3 width=7 by coafter_fwd_at, ex_intro/
 qed-.
 
-lemma coafter_fwd_istot_dx: ∀f2,f1,f. f2 ~⊚ f1 ≘ f → 𝐓⦃f⦄ → 𝐓⦃f1⦄.
+lemma coafter_fwd_istot_dx: ∀f2,f1,f. f2 ~⊚ f1 ≘ f → 𝐓❪f❫ → 𝐓❪f1❫.
 #f2 #f1 #f #H #Hf #i1 elim (Hf i1) -Hf
 #i2 #Hf elim (coafter_at_fwd … Hf … H) -f /2 width=2 by ex_intro/
 qed-.
 
-lemma coafter_fwd_istot_sn: ∀f2,f1,f. f2 ~⊚ f1 ≘ f → 𝐓⦃f⦄ → 𝐓⦃f2⦄.
+lemma coafter_fwd_istot_sn: ∀f2,f1,f. f2 ~⊚ f1 ≘ f → 𝐓❪f❫ → 𝐓❪f2❫.
 #f2 #f1 #f #H #Hf #i1 elim (Hf i1) -Hf
 #i #Hf elim (coafter_at_fwd … Hf … H) -f
 #i2 #Hf1 #Hf2 lapply (at_increasing … Hf1) -f1
 #Hi12 elim (at_le_ex … Hf2 … Hi12) -i2 /2 width=2 by ex_intro/
 qed-.
 
-lemma coafter_inv_istot: ∀f2,f1,f. f2 ~⊚ f1 ≘ f → 𝐓⦃f⦄ → 𝐓⦃f2⦄ ∧ 𝐓⦃f1⦄.
+lemma coafter_inv_istot: ∀f2,f1,f. f2 ~⊚ f1 ≘ f → 𝐓❪f❫ → 𝐓❪f2❫ ∧ 𝐓❪f1❫.
 /3 width=4 by coafter_fwd_istot_sn, coafter_fwd_istot_dx, conj/ qed-.
 
-lemma coafter_at1_fwd: ∀f1,i1,i2. @⦃i1, f1⦄ ≘ i2 → ∀f2. 𝐓⦃f2⦄ → ∀f. f2 ~⊚ f1 ≘ f →
-                     ∃∃i. @⦃i2, f2⦄ ≘ i & @⦃i1, f⦄ ≘ i.
+lemma coafter_at1_fwd: ∀f1,i1,i2. @❪i1, f1❫ ≘ i2 → ∀f2. 𝐓❪f2❫ → ∀f. f2 ~⊚ f1 ≘ f →
+                     ∃∃i. @❪i2, f2❫ ≘ i & @❪i1, f❫ ≘ i.
 #f1 #i1 #i2 #Hf1 #f2 #Hf2 #f #Hf elim (Hf2 i2) -Hf2
 /3 width=8 by coafter_fwd_at, ex2_intro/
 qed-.
 
-lemma coafter_fwd_isid_sn: ∀f2,f1,f. 𝐓⦃f⦄ → f2 ~⊚ f1 ≘ f → f1 ≡ f → 𝐈⦃f2⦄.
+lemma coafter_fwd_isid_sn: ∀f2,f1,f. 𝐓❪f❫ → f2 ~⊚ f1 ≘ f → f1 ≡ f → 𝐈❪f2❫.
 #f2 #f1 #f #H #Hf elim (coafter_inv_istot … Hf H) -H
 #Hf2 #Hf1 #H @isid_at_total // -Hf2
 #i2 #i #Hf2 elim (Hf1 i2) -Hf1
@@ -570,14 +570,14 @@ lemma coafter_fwd_isid_sn: ∀f2,f1,f. 𝐓⦃f⦄ → f2 ~⊚ f1 ≘ f → f1 
 /3 width=7 by at_eq_repl_back, at_mono, at_id_le/
 qed-.
 
-lemma coafter_fwd_isid_dx: ∀f2,f1,f.  𝐓⦃f⦄ → f2 ~⊚ f1 ≘ f → f2 ≡ f → 𝐈⦃f1⦄.
+lemma coafter_fwd_isid_dx: ∀f2,f1,f.  𝐓❪f❫ → f2 ~⊚ f1 ≘ f → f2 ≡ f → 𝐈❪f1❫.
 #f2 #f1 #f #H #Hf elim (coafter_inv_istot … Hf H) -H
 #Hf2 #Hf1 #H2 @isid_at_total // -Hf1
 #i1 #i2 #Hi12 elim (coafter_at1_fwd … Hi12 … Hf) -f1
 /3 width=8 by at_inj, at_eq_repl_back/
 qed-.
 *)
-corec fact coafter_inj_O_aux: ∀f1. @⦃0, f1⦄ ≘ 0 → H_coafter_inj f1.
+corec fact coafter_inj_O_aux: ∀f1. @❪0, f1❫ ≘ 0 → H_coafter_inj f1.
 #f1 #H1f1 #H2f1 #f #f21 #f22 #H1f #H2f
 cases (at_inv_pxp … H1f1) -H1f1 [ |*: // ] #g1 #H1
 lapply (istot_inv_push … H2f1 … H1) -H2f1 #H2g1
@@ -592,8 +592,8 @@ cases (coafter_inv_pxx … H1f … H1) -H1f * #g21 #g #H1g #H21 #H
 /2 width=1 by coafter_tls, istot_tls, at_pxx_tls/
 qed-.
 
-fact coafter_inj_aux: (∀f1. @⦃0, f1⦄ ≘ 0 → H_coafter_inj f1) →
-                      ∀i2,f1. @⦃0, f1⦄ ≘ i2 → H_coafter_inj f1.
+fact coafter_inj_aux: (∀f1. @❪0, f1❫ ≘ 0 → H_coafter_inj f1) →
+                      ∀i2,f1. @❪0, f1❫ ≘ i2 → H_coafter_inj f1.
 #H0 #i2 elim i2 -i2 /2 width=1 by/ -H0
 #i2 #IH #f1 #H1f1 #H2f1 #f #f21 #f22 #H1f #H2f
 elim (at_inv_pxn … H1f1) -H1f1 [ |*: // ] #g1 #H1g1 #H1
@@ -606,7 +606,7 @@ theorem coafter_inj: ∀f1. H_coafter_inj f1.
 #f1 #H cases (H 0) /3 width=7 by coafter_inj_aux, coafter_inj_O_aux/
 qed-.
 
-corec fact coafter_fwd_isid2_O_aux: ∀f1. @⦃0, f1⦄ ≘ 0 →
+corec fact coafter_fwd_isid2_O_aux: ∀f1. @❪0, f1❫ ≘ 0 →
                                     H_coafter_fwd_isid2 f1.
 #f1 #H1f1 #f2 #f #H #H2f1 #Hf
 cases (at_inv_pxp … H1f1) -H1f1 [ |*: // ] #g1 #H1
@@ -620,8 +620,8 @@ cases (coafter_inv_pxx … H … H1) -H * #g2 #g #H #H2 #H0
 ]
 qed-.
 
-fact coafter_fwd_isid2_aux: (∀f1. @⦃0, f1⦄ ≘ 0 → H_coafter_fwd_isid2 f1) →
-                            ∀i2,f1. @⦃0, f1⦄ ≘ i2 → H_coafter_fwd_isid2 f1.
+fact coafter_fwd_isid2_aux: (∀f1. @❪0, f1❫ ≘ 0 → H_coafter_fwd_isid2 f1) →
+                            ∀i2,f1. @❪0, f1❫ ≘ i2 → H_coafter_fwd_isid2 f1.
 #H0 #i2 elim i2 -i2 /2 width=1 by/ -H0
 #i2 #IH #f1 #H1f1 #f2 #f #H #H2f1 #Hf
 elim (at_inv_pxn … H1f1) -H1f1 [ |*: // ] #g1 #Hg1 #H1
@@ -634,7 +634,7 @@ lemma coafter_fwd_isid2: ∀f1. H_coafter_fwd_isid2 f1.
 /3 width=7 by coafter_fwd_isid2_aux, coafter_fwd_isid2_O_aux/
 qed-.
 
-fact coafter_isfin2_fwd_O_aux: ∀f1. @⦃0, f1⦄ ≘ 0 →
+fact coafter_isfin2_fwd_O_aux: ∀f1. @❪0, f1❫ ≘ 0 →
                                H_coafter_isfin2_fwd f1.
 #f1 #Hf1 #f2 #H
 generalize in match Hf1; generalize in match f1; -f1
@@ -649,8 +649,8 @@ elim (Hg1 0) #n #Hn
 /5 width=6 by isfin_next, isfin_push, isfin_inv_tls, istot_tls, at_pxx_tls, coafter_tls_O/
 qed-.
 
-fact coafter_isfin2_fwd_aux: (∀f1. @⦃0, f1⦄ ≘ 0 → H_coafter_isfin2_fwd f1) →
-                             ∀i2,f1. @⦃0, f1⦄ ≘ i2 → H_coafter_isfin2_fwd f1.
+fact coafter_isfin2_fwd_aux: (∀f1. @❪0, f1❫ ≘ 0 → H_coafter_isfin2_fwd f1) →
+                             ∀i2,f1. @❪0, f1❫ ≘ i2 → H_coafter_isfin2_fwd f1.
 #H0 #i2 elim i2 -i2 /2 width=1 by/ -H0
 #i2 #IH #f1 #H1f1 #f2 #Hf2 #H2f1 #f #Hf
 elim (at_inv_pxn … H1f1) -H1f1 [ |*: // ] #g1 #Hg1 #H1
@@ -664,7 +664,7 @@ lemma coafter_isfin2_fwd: ∀f1. H_coafter_isfin2_fwd f1.
 /3 width=7 by coafter_isfin2_fwd_aux, coafter_isfin2_fwd_O_aux/
 qed-.
 
-lemma coafter_inv_sor: ∀f. 𝐅⦃f⦄ → ∀f2. 𝐓⦃f2⦄ → ∀f1. f2 ~⊚ f1 ≘ f → ∀fa,fb. fa ⋓ fb ≘ f →
+lemma coafter_inv_sor: ∀f. 𝐅❪f❫ → ∀f2. 𝐓❪f2❫ → ∀f1. f2 ~⊚ f1 ≘ f → ∀fa,fb. fa ⋓ fb ≘ f →
                        ∃∃f1a,f1b. f2 ~⊚ f1a ≘ fa & f2 ~⊚ f1b ≘ fb & f1a ⋓ f1b ≘ f1.
 @isfin_ind
 [ #f #Hf #f2 #Hf2 #f1 #H1f #fa #fb #H2f
@@ -688,7 +688,7 @@ qed-.
 
 (* Properties with istot ****************************************************)
 
-lemma coafter_sor: ∀f. 𝐅⦃f⦄ → ∀f2. 𝐓⦃f2⦄ → ∀f1. f2 ~⊚ f1 ≘ f → ∀f1a,f1b. f1a ⋓ f1b ≘ f1 →
+lemma coafter_sor: ∀f. 𝐅❪f❫ → ∀f2. 𝐓❪f2❫ → ∀f1. f2 ~⊚ f1 ≘ f → ∀f1a,f1b. f1a ⋓ f1b ≘ f1 →
                    ∃∃fa,fb. f2 ~⊚ f1a ≘ fa & f2 ~⊚ f1b ≘ fb & fa ⋓ fb ≘ f.
 @isfin_ind
 [ #f #Hf #f2 #Hf2 #f1 #Hf #f1a #f1b #Hf1