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15 include "basic_2/notation/relations/lrsubeqf_4.ma".
16 include "basic_2/static/frees.ma".
18 (* RESTRICTED REFINEMENT FOR CONTEXT-SENSITIVE FREE VARIABLES ***************)
20 inductive lsubf: relation4 lenv rtmap lenv rtmap ≝
21 | lsubf_atom: ∀f1,f2. f1 ≗ f2 → lsubf (⋆) f1 (⋆) f2
22 | lsubf_push: ∀f1,f2,I1,I2,L1,L2. lsubf L1 (f1) L2 (f2) →
23 lsubf (L1.ⓘ{I1}) (↑f1) (L2.ⓘ{I2}) (↑f2)
24 | lsubf_bind: ∀f1,f2,I,L1,L2. lsubf L1 f1 L2 f2 →
25 lsubf (L1.ⓘ{I}) (⫯f1) (L2.ⓘ{I}) (⫯f2)
26 | lsubf_beta: ∀f,f0,f1,f2,L1,L2,W,V. L1 ⊢ 𝐅*⦃V⦄ ≡ f → f0 ⋓ f ≡ f1 →
27 lsubf L1 f0 L2 f2 → lsubf (L1.ⓓⓝW.V) (⫯f1) (L2.ⓛW) (⫯f2)
28 | lsubf_unit: ∀f,f0,f1,f2,I1,I2,L1,L2,V. L1 ⊢ 𝐅*⦃V⦄ ≡ f → f0 ⋓ f ≡ f1 →
29 lsubf L1 f0 L2 f2 → lsubf (L1.ⓑ{I1}V) (⫯f1) (L2.ⓤ{I2}) (⫯f2)
33 "local environment refinement (context-sensitive free variables)"
34 'LRSubEqF L1 f1 L2 f2 = (lsubf L1 f1 L2 f2).
36 (* Basic inversion lemmas ***************************************************)
38 fact lsubf_inv_atom1_aux: ∀f1,f2,L1,L2. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄ → L1 = ⋆ →
40 #f1 #f2 #L1 #L2 * -f1 -f2 -L1 -L2
42 | #f1 #f2 #I1 #I2 #L1 #L2 #_ #H destruct
43 | #f1 #f2 #I #L1 #L2 #_ #H destruct
44 | #f #f0 #f1 #f2 #L1 #L2 #W #V #_ #_ #_ #H destruct
45 | #f #f0 #f1 #f2 #I1 #I2 #L1 #L2 #V #_ #_ #_ #H destruct
49 lemma lsubf_inv_atom1: ∀f1,f2,L2. ⦃⋆, f1⦄ ⫃𝐅* ⦃L2, f2⦄ → f1 ≗ f2 ∧ L2 = ⋆.
50 /2 width=3 by lsubf_inv_atom1_aux/ qed-.
52 fact lsubf_inv_push1_aux: ∀f1,f2,L1,L2. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄ →
53 ∀g1,I1,K1. f1 = ↑g1 → L1 = K1.ⓘ{I1} →
54 ∃∃g2,I2,K2. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f2 = ↑g2 & L2 = K2.ⓘ{I2}.
55 #f1 #f2 #L1 #L2 * -f1 -f2 -L1 -L2
56 [ #f1 #f2 #_ #g1 #J1 #K1 #_ #H destruct
57 | #f1 #f2 #I1 #I2 #L1 #L2 #H12 #g1 #J1 #K1 #H1 #H2 destruct
58 <(injective_push … H1) -g1 /2 width=6 by ex3_3_intro/
59 | #f1 #f2 #I #L1 #L2 #_ #g1 #J1 #K1 #H elim (discr_next_push … H)
60 | #f #f0 #f1 #f2 #L1 #L2 #W #V #_ #_ #_ #g1 #J1 #K1 #H elim (discr_next_push … H)
61 | #f #f0 #f1 #f2 #I1 #I2 #L1 #L2 #V #_ #_ #_ #g1 #J1 #K1 #H elim (discr_next_push … H)
65 lemma lsubf_inv_push1: ∀g1,f2,I1,K1,L2. ⦃K1.ⓘ{I1}, ↑g1⦄ ⫃𝐅* ⦃L2, f2⦄ →
66 ∃∃g2,I2,K2. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f2 = ↑g2 & L2 = K2.ⓘ{I2}.
67 /2 width=6 by lsubf_inv_push1_aux/ qed-.
69 fact lsubf_inv_pair1_aux: ∀f1,f2,L1,L2. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄ →
70 ∀g1,I,K1,X. f1 = ⫯g1 → L1 = K1.ⓑ{I}X →
71 ∨∨ ∃∃g2,K2. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f2 = ⫯g2 & L2 = K2.ⓑ{I}X
72 | ∃∃g,g0,g2,K2,W,V. ⦃K1, g0⦄ ⫃𝐅* ⦃K2, g2⦄ &
73 K1 ⊢ 𝐅*⦃V⦄ ≡ g & g0 ⋓ g ≡ g1 & f2 = ⫯g2 &
74 I = Abbr & X = ⓝW.V & L2 = K2.ⓛW
75 | ∃∃g,g0,g2,J,K2. ⦃K1, g0⦄ ⫃𝐅* ⦃K2, g2⦄ &
76 K1 ⊢ 𝐅*⦃X⦄ ≡ g & g0 ⋓ g ≡ g1 & f2 = ⫯g2 &
78 #f1 #f2 #L1 #L2 * -f1 -f2 -L1 -L2
79 [ #f1 #f2 #_ #g1 #J #K1 #X #_ #H destruct
80 | #f1 #f2 #I1 #I2 #L1 #L2 #H12 #g1 #J #K1 #X #H elim (discr_push_next … H)
81 | #f1 #f2 #I #L1 #L2 #H12 #g1 #J #K1 #X #H1 #H2 destruct
82 <(injective_next … H1) -g1 /3 width=5 by or3_intro0, ex3_2_intro/
83 | #f #f0 #f1 #f2 #L1 #L2 #W #V #Hf #Hf1 #H12 #g1 #J #K1 #X #H1 #H2 destruct
84 <(injective_next … H1) -g1 /3 width=12 by or3_intro1, ex7_6_intro/
85 | #f #f0 #f1 #f2 #I1 #I2 #L1 #L2 #V #Hf #Hf1 #H12 #g1 #J #K1 #X #H1 #H2 destruct
86 <(injective_next … H1) -g1 /3 width=10 by or3_intro2, ex5_5_intro/
90 lemma lsubf_inv_pair1: ∀g1,f2,I,K1,L2,X. ⦃K1.ⓑ{I}X, ⫯g1⦄ ⫃𝐅* ⦃L2, f2⦄ →
91 ∨∨ ∃∃g2,K2. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f2 = ⫯g2 & L2 = K2.ⓑ{I}X
92 | ∃∃g,g0,g2,K2,W,V. ⦃K1, g0⦄ ⫃𝐅* ⦃K2, g2⦄ &
93 K1 ⊢ 𝐅*⦃V⦄ ≡ g & g0 ⋓ g ≡ g1 & f2 = ⫯g2 &
94 I = Abbr & X = ⓝW.V & L2 = K2.ⓛW
95 | ∃∃g,g0,g2,J,K2. ⦃K1, g0⦄ ⫃𝐅* ⦃K2, g2⦄ &
96 K1 ⊢ 𝐅*⦃X⦄ ≡ g & g0 ⋓ g ≡ g1 & f2 = ⫯g2 &
98 /2 width=5 by lsubf_inv_pair1_aux/ qed-.
100 fact lsubf_inv_unit1_aux: ∀f1,f2,L1,L2. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄ →
101 ∀g1,I,K1. f1 = ⫯g1 → L1 = K1.ⓤ{I} →
102 ∃∃g2,K2. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f2 = ⫯g2 & L2 = K2.ⓤ{I}.
103 #f1 #f2 #L1 #L2 * -f1 -f2 -L1 -L2
104 [ #f1 #f2 #_ #g1 #J #K1 #_ #H destruct
105 | #f1 #f2 #I1 #I2 #L1 #L2 #H12 #g1 #J #K1 #H elim (discr_push_next … H)
106 | #f1 #f2 #I #L1 #L2 #H12 #g1 #J #K1 #H1 #H2 destruct
107 <(injective_next … H1) -g1 /2 width=5 by ex3_2_intro/
108 | #f #f0 #f1 #f2 #L1 #L2 #W #V #_ #_ #_ #g1 #J #K1 #_ #H destruct
109 | #f #f0 #f1 #f2 #I1 #I2 #L1 #L2 #V #_ #_ #_ #g1 #J #K1 #_ #H destruct
113 lemma lsubf_inv_unit1: ∀g1,f2,I,K1,L2. ⦃K1.ⓤ{I}, ⫯g1⦄ ⫃𝐅* ⦃L2, f2⦄ →
114 ∃∃g2,K2. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f2 = ⫯g2 & L2 = K2.ⓤ{I}.
115 /2 width=5 by lsubf_inv_unit1_aux/ qed-.
117 fact lsubf_inv_atom2_aux: ∀f1,f2,L1,L2. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄ → L2 = ⋆ →
119 #f1 #f2 #L1 #L2 * -f1 -f2 -L1 -L2
120 [ /2 width=1 by conj/
121 | #f1 #f2 #I1 #I2 #L1 #L2 #_ #H destruct
122 | #f1 #f2 #I #L1 #L2 #_ #H destruct
123 | #f #f0 #f1 #f2 #L1 #L2 #W #V #_ #_ #_ #H destruct
124 | #f #f0 #f1 #f2 #I1 #I2 #L1 #L2 #V #_ #_ #_ #H destruct
128 lemma lsubf_inv_atom2: ∀f1,f2,L1. ⦃L1, f1⦄ ⫃𝐅* ⦃⋆, f2⦄ → f1 ≗ f2 ∧ L1 = ⋆.
129 /2 width=3 by lsubf_inv_atom2_aux/ qed-.
131 fact lsubf_inv_push2_aux: ∀f1,f2,L1,L2. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄ →
132 ∀g2,I2,K2. f2 = ↑g2 → L2 = K2.ⓘ{I2} →
133 ∃∃g1,I1,K1. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f1 = ↑g1 & L1 = K1.ⓘ{I1}.
134 #f1 #f2 #L1 #L2 * -f1 -f2 -L1 -L2
135 [ #f1 #f2 #_ #g2 #J2 #K2 #_ #H destruct
136 | #f1 #f2 #I1 #I2 #L1 #L2 #H12 #g2 #J2 #K2 #H1 #H2 destruct
137 <(injective_push … H1) -g2 /2 width=6 by ex3_3_intro/
138 | #f1 #f2 #I #L1 #L2 #_ #g2 #J2 #K2 #H elim (discr_next_push … H)
139 | #f #f0 #f1 #f2 #L1 #L2 #W #V #_ #_ #_ #g2 #J2 #K2 #H elim (discr_next_push … H)
140 | #f #f0 #f1 #f2 #I1 #I2 #L1 #L2 #V #_ #_ #_ #g2 #J2 #K2 #H elim (discr_next_push … H)
144 lemma lsubf_inv_push2: ∀f1,g2,I2,L1,K2. ⦃L1, f1⦄ ⫃𝐅* ⦃K2.ⓘ{I2}, ↑g2⦄ →
145 ∃∃g1,I1,K1. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f1 = ↑g1 & L1 = K1.ⓘ{I1}.
146 /2 width=6 by lsubf_inv_push2_aux/ qed-.
148 fact lsubf_inv_pair2_aux: ∀f1,f2,L1,L2. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄ →
149 ∀g2,I,K2,W. f2 = ⫯g2 → L2 = K2.ⓑ{I}W →
150 ∨∨ ∃∃g1,K1. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f1 = ⫯g1 & L1 = K1.ⓑ{I}W
151 | ∃∃g,g0,g1,K1,V. ⦃K1, g0⦄ ⫃𝐅* ⦃K2, g2⦄ &
152 K1 ⊢ 𝐅*⦃V⦄ ≡ g & g0 ⋓ g ≡ g1 & f1 = ⫯g1 &
153 I = Abst & L1 = K1.ⓓⓝW.V.
154 #f1 #f2 #L1 #L2 * -f1 -f2 -L1 -L2
155 [ #f1 #f2 #_ #g2 #J #K2 #X #_ #H destruct
156 | #f1 #f2 #I1 #I2 #L1 #L2 #H12 #g2 #J #K2 #X #H elim (discr_push_next … H)
157 | #f1 #f2 #I #L1 #L2 #H12 #g2 #J #K2 #X #H1 #H2 destruct
158 <(injective_next … H1) -g2 /3 width=5 by ex3_2_intro, or_introl/
159 | #f #f0 #f1 #f2 #L1 #L2 #W #V #Hf #Hf1 #H12 #g2 #J #K2 #X #H1 #H2 destruct
160 <(injective_next … H1) -g2 /3 width=10 by ex6_5_intro, or_intror/
161 | #f #f0 #f1 #f2 #I1 #I2 #L1 #L2 #V #_ #_ #_ #g2 #J #K2 #X #_ #H destruct
165 lemma lsubf_inv_pair2: ∀f1,g2,I,L1,K2,W. ⦃L1, f1⦄ ⫃𝐅* ⦃K2.ⓑ{I}W, ⫯g2⦄ →
166 ∨∨ ∃∃g1,K1. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f1 = ⫯g1 & L1 = K1.ⓑ{I}W
167 | ∃∃g,g0,g1,K1,V. ⦃K1, g0⦄ ⫃𝐅* ⦃K2, g2⦄ &
168 K1 ⊢ 𝐅*⦃V⦄ ≡ g & g0 ⋓ g ≡ g1 & f1 = ⫯g1 &
169 I = Abst & L1 = K1.ⓓⓝW.V.
170 /2 width=5 by lsubf_inv_pair2_aux/ qed-.
172 fact lsubf_inv_unit2_aux: ∀f1,f2,L1,L2. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄ →
173 ∀g2,I,K2. f2 = ⫯g2 → L2 = K2.ⓤ{I} →
174 ∨∨ ∃∃g1,K1. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f1 = ⫯g1 & L1 = K1.ⓤ{I}
175 | ∃∃g,g0,g1,J,K1,V. ⦃K1, g0⦄ ⫃𝐅* ⦃K2, g2⦄ &
176 K1 ⊢ 𝐅*⦃V⦄ ≡ g & g0 ⋓ g ≡ g1 & f1 = ⫯g1 &
178 #f1 #f2 #L1 #L2 * -f1 -f2 -L1 -L2
179 [ #f1 #f2 #_ #g2 #J #K2 #_ #H destruct
180 | #f1 #f2 #I1 #I2 #L1 #L2 #H12 #g2 #J #K2 #H elim (discr_push_next … H)
181 | #f1 #f2 #I #L1 #L2 #H12 #g2 #J #K2 #H1 #H2 destruct
182 <(injective_next … H1) -g2 /3 width=5 by ex3_2_intro, or_introl/
183 | #f #f0 #f1 #f2 #L1 #L2 #W #V #_ #_ #_ #g2 #J #K2 #_ #H destruct
184 | #f #f0 #f1 #f2 #I1 #I2 #L1 #L2 #V #Hf #Hf1 #H12 #g2 #J #K2 #H1 #H2 destruct
185 <(injective_next … H1) -g2 /3 width=11 by ex5_6_intro, or_intror/
189 lemma lsubf_inv_unit2: ∀f1,g2,I,L1,K2. ⦃L1, f1⦄ ⫃𝐅* ⦃K2.ⓤ{I}, ⫯g2⦄ →
190 ∨∨ ∃∃g1,K1. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f1 = ⫯g1 & L1 = K1.ⓤ{I}
191 | ∃∃g,g0,g1,J,K1,V. ⦃K1, g0⦄ ⫃𝐅* ⦃K2, g2⦄ &
192 K1 ⊢ 𝐅*⦃V⦄ ≡ g & g0 ⋓ g ≡ g1 & f1 = ⫯g1 &
194 /2 width=5 by lsubf_inv_unit2_aux/ qed-.
196 (* Advanced inversion lemmas ************************************************)
198 lemma lsubf_inv_atom: ∀f1,f2. ⦃⋆, f1⦄ ⫃𝐅* ⦃⋆, f2⦄ → f1 ≗ f2.
199 #f1 #f2 #H elim (lsubf_inv_atom1 … H) -H //
202 lemma lsubf_inv_push_sn: ∀g1,f2,I1,I2,K1,K2. ⦃K1.ⓘ{I1}, ↑g1⦄ ⫃𝐅* ⦃K2.ⓘ{I2}, f2⦄ →
203 ∃∃g2. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f2 = ↑g2.
204 #g1 #f2 #I #K1 #K2 #X #H elim (lsubf_inv_push1 … H) -H
205 #g2 #I #Y #H0 #H2 #H destruct /2 width=3 by ex2_intro/
208 lemma lsubf_inv_bind_sn: ∀g1,f2,I,K1,K2. ⦃K1.ⓘ{I}, ⫯g1⦄ ⫃𝐅* ⦃K2.ⓘ{I}, f2⦄ →
209 ∃∃g2. ⦃K1, g1⦄ ⫃𝐅* ⦃K2, g2⦄ & f2 = ⫯g2.
210 #g1 #f2 * #I [2: #X ] #K1 #K2 #H
211 [ elim (lsubf_inv_pair1 … H) -H *
212 [ #z2 #Y2 #H2 #H #H0 destruct /2 width=3 by ex2_intro/
213 | #z #z0 #z2 #Y2 #W #V #_ #_ #_ #_ #H0 #_ #H destruct
214 | #z #z0 #z2 #Z2 #Y2 #_ #_ #_ #_ #H destruct
216 | elim (lsubf_inv_unit1 … H) -H
217 #z2 #Y2 #H2 #H #H0 destruct /2 width=3 by ex2_intro/
221 lemma lsubf_inv_beta_sn: ∀g1,f2,K1,K2,V,W. ⦃K1.ⓓⓝW.V, ⫯g1⦄ ⫃𝐅* ⦃K2.ⓛW, f2⦄ →
222 ∃∃g,g0,g2. ⦃K1, g0⦄ ⫃𝐅* ⦃K2, g2⦄ & K1 ⊢ 𝐅*⦃V⦄ ≡ g & g0 ⋓ g ≡ g1 & f2 = ⫯g2.
223 #g1 #f2 #K1 #K2 #V #W #H elim (lsubf_inv_pair1 … H) -H *
224 [ #z2 #Y2 #_ #_ #H destruct
225 | #z #z0 #z2 #Y2 #X0 #X #H02 #Hz #Hg1 #H #_ #H0 #H1 destruct
226 /2 width=7 by ex4_3_intro/
227 | #z #z0 #z2 #Z2 #Y2 #_ #_ #_ #_ #H destruct
231 lemma lsubf_inv_unit_sn: ∀g1,f2,I,J,K1,K2,V. ⦃K1.ⓑ{I}V, ⫯g1⦄ ⫃𝐅* ⦃K2.ⓤ{J}, f2⦄ →
232 ∃∃g,g0,g2. ⦃K1, g0⦄ ⫃𝐅* ⦃K2, g2⦄ & K1 ⊢ 𝐅*⦃V⦄ ≡ g & g0 ⋓ g ≡ g1 & f2 = ⫯g2.
233 #g1 #f2 #I #J #K1 #K2 #V #H elim (lsubf_inv_pair1 … H) -H *
234 [ #z2 #Y2 #_ #_ #H destruct
235 | #z #z0 #z2 #Y2 #X0 #X #_ #_ #_ #_ #_ #_ #H destruct
236 | #z #z0 #z2 #Z2 #Y2 #H02 #Hz #Hg1 #H0 #H1 destruct
237 /2 width=7 by ex4_3_intro/
241 lemma lsubf_inv_refl: ∀L,f1,f2. ⦃L,f1⦄ ⫃𝐅* ⦃L,f2⦄ → f1 ≗ f2.
242 #L elim L -L /2 width=1 by lsubf_inv_atom/
243 #L #I #IH #f1 #f2 #H12
244 elim (pn_split f1) * #g1 #H destruct
245 [ elim (lsubf_inv_push_sn … H12) | elim (lsubf_inv_bind_sn … H12) ] -H12
246 #g2 #H12 #H destruct /3 width=5 by eq_next, eq_push/
249 (* Basic forward lemmas *****************************************************)
251 lemma lsubf_fwd_bind_tl: ∀f1,f2,I,L1,L2.
252 ⦃L1.ⓘ{I}, f1⦄ ⫃𝐅* ⦃L2.ⓘ{I}, f2⦄ → ⦃L1, ⫱f1⦄ ⫃𝐅* ⦃L2, ⫱f2⦄.
253 #f1 #f2 #I #L1 #L2 #H
254 elim (pn_split f1) * #g1 #H0 destruct
255 [ elim (lsubf_inv_push_sn … H) | elim (lsubf_inv_bind_sn … H) ] -H
256 #g2 #H12 #H destruct //
259 lemma lsubf_fwd_isid_dx: ∀f1,f2,L1,L2. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄ → 𝐈⦃f2⦄ → 𝐈⦃f1⦄.
260 #f1 #f2 #L1 #L2 #H elim H -f1 -f2 -L1 -L2
261 [ /2 width=3 by isid_eq_repl_fwd/
262 | /4 width=3 by isid_inv_push, isid_push/
263 | #f1 #f2 #I #L1 #L2 #_ #_ #H elim (isid_inv_next … H) -H //
264 | #f #f0 #f1 #f2 #L1 #L2 #W #V #_ #_ #_ #_ #H elim (isid_inv_next … H) -H //
265 | #f #f0 #f1 #f2 #I1 #I2 #L1 #L2 #V #_ #_ #_ #_ #H elim (isid_inv_next … H) -H //
269 lemma lsubf_fwd_isid_sn: ∀f1,f2,L1,L2. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄ → 𝐈⦃f1⦄ → 𝐈⦃f2⦄.
270 #f1 #f2 #L1 #L2 #H elim H -f1 -f2 -L1 -L2
271 [ /2 width=3 by isid_eq_repl_back/
272 | /4 width=3 by isid_inv_push, isid_push/
273 | #f1 #f2 #I #L1 #L2 #_ #_ #H elim (isid_inv_next … H) -H //
274 | #f #f0 #f1 #f2 #L1 #L2 #W #V #_ #_ #_ #_ #H elim (isid_inv_next … H) -H //
275 | #f #f0 #f1 #f2 #I1 #I2 #L1 #L2 #V #_ #_ #_ #_ #H elim (isid_inv_next … H) -H //
279 lemma lsubf_fwd_sle: ∀f1,f2,L1,L2. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄ → f2 ⊆ f1.
280 #f1 #f2 #L1 #L2 #H elim H -f1 -f2 -L1 -L2
281 /3 width=5 by sor_inv_sle_sn_trans, sle_next, sle_push, sle_refl_eq, eq_sym/
284 (* Basic properties *********************************************************)
286 axiom lsubf_eq_repl_back1: ∀f2,L1,L2. eq_repl_back … (λf1. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄).
288 lemma lsubf_eq_repl_fwd1: ∀f2,L1,L2. eq_repl_fwd … (λf1. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄).
289 #f2 #L1 #L2 @eq_repl_sym /2 width=3 by lsubf_eq_repl_back1/
292 axiom lsubf_eq_repl_back2: ∀f1,L1,L2. eq_repl_back … (λf2. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄).
294 lemma lsubf_eq_repl_fwd2: ∀f1,L1,L2. eq_repl_fwd … (λf2. ⦃L1, f1⦄ ⫃𝐅* ⦃L2, f2⦄).
295 #f1 #L1 #L2 @eq_repl_sym /2 width=3 by lsubf_eq_repl_back2/
298 lemma lsubf_refl: bi_reflexive … lsubf.
299 #L elim L -L /2 width=1 by lsubf_atom, eq_refl/
300 #L #I #IH #f elim (pn_split f) * #g #H destruct
301 /2 width=1 by lsubf_push, lsubf_bind/
304 lemma lsubf_refl_eq: ∀f1,f2,L. f1 ≗ f2 → ⦃L, f1⦄ ⫃𝐅* ⦃L, f2⦄.
305 /2 width=3 by lsubf_eq_repl_back2/ qed.
307 lemma lsubf_tl_dx: ∀g1,f2,I,L1,L2. ⦃L1, g1⦄ ⫃𝐅* ⦃L2, ⫱f2⦄ →
308 ∃∃f1. ⦃L1.ⓘ{I}, f1⦄ ⫃𝐅* ⦃L2.ⓘ{I}, f2⦄ & g1 = ⫱f1.
309 #g1 #f2 #I #L1 #L2 #H
310 elim (pn_split f2) * #g2 #H2 destruct
311 @ex2_intro [1,2,4,5: /2 width=2 by lsubf_push, lsubf_bind/ ] // (**) (* constructor needed *)