(* Main properties **********************************************************)
-theorem liftsb_div3: â\88\80f2,I,I2. â¬\86*[f2] I2 â\89\98 I â\86\92 â\88\80f,I1. â¬\86*[f] I1 ≘ I →
- â\88\80f1. f2 â\8a\9a f1 â\89\98 f â\86\92 â¬\86*[f1] I1 ≘ I2.
+theorem liftsb_div3: â\88\80f2,I,I2. â\87§*[f2] I2 â\89\98 I â\86\92 â\88\80f,I1. â\87§*[f] I1 ≘ I →
+ â\88\80f1. f2 â\8a\9a f1 â\89\98 f â\86\92 â\87§*[f1] I1 ≘ I2.
#f2 #I #I2 * -I -I2 #I [2: #V #V2 #HV2 ] #f #I1 #H
[ elim (liftsb_inv_pair_dx … H) | lapply (liftsb_inv_unit_dx … H) ] -H
/3 width=6 by lifts_div3, ext2_pair, ext2_unit/
qed-.
-theorem liftsb_trans: â\88\80f1,I1,I. â¬\86*[f1] I1 â\89\98 I â\86\92 â\88\80f2,I2. â¬\86*[f2] I ≘ I2 →
- â\88\80f. f2 â\8a\9a f1 â\89\98 f â\86\92 â¬\86*[f] I1 ≘ I2.
+theorem liftsb_trans: â\88\80f1,I1,I. â\87§*[f1] I1 â\89\98 I â\86\92 â\88\80f2,I2. â\87§*[f2] I ≘ I2 →
+ â\88\80f. f2 â\8a\9a f1 â\89\98 f â\86\92 â\87§*[f] I1 ≘ I2.
#f1 #I1 #I * -I1 -I #I1 [2: #V1 #V #HV1 ] #f2 #I2 #H
[ elim (liftsb_inv_pair_sn … H) | lapply (liftsb_inv_unit_sn … H) ] -H
/3 width=6 by lifts_trans, ext2_pair, ext2_unit/
qed-.
-theorem liftsb_conf: â\88\80f1,I,I1. â¬\86*[f1] I â\89\98 I1 â\86\92 â\88\80f,I2. â¬\86*[f] I ≘ I2 →
- â\88\80f2. f2 â\8a\9a f1 â\89\98 f â\86\92 â¬\86*[f2] I1 ≘ I2.
+theorem liftsb_conf: â\88\80f1,I,I1. â\87§*[f1] I â\89\98 I1 â\86\92 â\88\80f,I2. â\87§*[f] I ≘ I2 →
+ â\88\80f2. f2 â\8a\9a f1 â\89\98 f â\86\92 â\87§*[f2] I1 ≘ I2.
#f1 #I #I1 * -I -I1 #I [2: #V #V1 #HV1 ] #f2 #I2 #H
[ elim (liftsb_inv_pair_sn … H) | lapply (liftsb_inv_unit_sn … H) ] -H
/3 width=6 by lifts_conf, ext2_pair, ext2_unit/
(* Advanced proprerties *****************************************************)
lemma liftsb_inj: ∀f. is_inj2 … (liftsb f).
-#f #T1 #U #H1 #T2 #H2 lapply (after_isid_dx 𝐈𝐝 … f)
+#f #T1 #U #H1 #T2 #H2 lapply (pr_after_isi_dx 𝐢 … f)
/3 width=6 by liftsb_div3, liftsb_fwd_isid/
qed-.
lemma liftsb_mono: ∀f,T. is_mono … (liftsb f T).
-#f #T #U1 #H1 #U2 #H2 lapply (after_isid_sn 𝐈𝐝 … f)
+#f #T #U1 #H1 #U2 #H2 lapply (pr_after_isi_sn 𝐢 … f)
/3 width=6 by liftsb_conf, liftsb_fwd_isid/
qed-.