qed. *)
theorem not_eq_to_le_to_lt: ∀n,m. n\ 5a title="leibnitz's non-equality" href="cic:/fakeuri.def(1)"\ 6≠\ 5/a\ 6m → n\ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6m → n\ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6m.
-#n #m #Hneq #Hle cases (\ 5a href="cic:/matita/arithmetics/nat/le_to_or_lt_eq.def(5)"\ 6le_to_or_lt_eq\ 5/a\ 6 ?? Hle) //
+#n #m #Hneq #Hle cases (\ 5a href="cic:/matita/arithmetics/nat/le_to_or_lt_eq.def(6)"\ 6le_to_or_lt_eq\ 5/a\ 6 ?? Hle) //
#Heq /3/ qed.
(*
nelim (Hneq Heq) qed. *)
∀m:\ 5a href="cic:/matita/arithmetics/nat/nat.ind(1,0,0)"\ 6nat\ 5/a\ 6. f \ 5a title="natural number" href="cic:/fakeuri.def(1)"\ 60\ 5/a\ 6 \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 m → \ 5a title="exists" href="cic:/fakeuri.def(1)"\ 6∃\ 5/a\ 6i. f i \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 m \ 5a title="logical and" href="cic:/fakeuri.def(1)"\ 6∧\ 5/a\ 6 m \ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6 f (\ 5a href="cic:/matita/arithmetics/nat/nat.con(0,2,0)"\ 6S\ 5/a\ 6 i).
#f #incr #m #lem (elim lem)
[@(\ 5a href="cic:/matita/basics/logic/ex.con(0,1,2)"\ 6ex_intro\ 5/a\ 6 ? ? \ 5a href="cic:/matita/arithmetics/nat/nat.con(0,1,0)"\ 6O\ 5/a\ 6) /2/
- |#n #len * #a * #len #ltnr (cases(\ 5a href="cic:/matita/arithmetics/nat/le_to_or_lt_eq.def(5)"\ 6le_to_or_lt_eq\ 5/a\ 6 … ltnr)) #H
+ |#n #len * #a * #len #ltnr (cases(\ 5a href="cic:/matita/arithmetics/nat/le_to_or_lt_eq.def(6)"\ 6le_to_or_lt_eq\ 5/a\ 6 … ltnr)) #H
[@(\ 5a href="cic:/matita/basics/logic/ex.con(0,1,2)"\ 6ex_intro\ 5/a\ 6 ? ? a) % /2/
|@(\ 5a href="cic:/matita/basics/logic/ex.con(0,1,2)"\ 6ex_intro\ 5/a\ 6 ? ? (\ 5a href="cic:/matita/arithmetics/nat/nat.con(0,2,0)"\ 6S\ 5/a\ 6 a)) % //
]
theorem increasing_to_injective: ∀f:\ 5a href="cic:/matita/arithmetics/nat/nat.ind(1,0,0)"\ 6nat\ 5/a\ 6 → \ 5a href="cic:/matita/arithmetics/nat/nat.ind(1,0,0)"\ 6nat\ 5/a\ 6.
\ 5a href="cic:/matita/arithmetics/nat/increasing.def(2)"\ 6increasing\ 5/a\ 6 f → \ 5a href="cic:/matita/basics/relations/injective.def(1)"\ 6injective\ 5/a\ 6 \ 5a href="cic:/matita/arithmetics/nat/nat.ind(1,0,0)"\ 6nat\ 5/a\ 6 \ 5a href="cic:/matita/arithmetics/nat/nat.ind(1,0,0)"\ 6nat\ 5/a\ 6 f.
#f #incr #n #m cases(\ 5a href="cic:/matita/arithmetics/nat/decidable_le.def(6)"\ 6decidable_le\ 5/a\ 6 n m)
- [#lenm cases(\ 5a href="cic:/matita/arithmetics/nat/le_to_or_lt_eq.def(5)"\ 6le_to_or_lt_eq\ 5/a\ 6 … lenm) //
+ [#lenm cases(\ 5a href="cic:/matita/arithmetics/nat/le_to_or_lt_eq.def(6)"\ 6le_to_or_lt_eq\ 5/a\ 6 … lenm) //
#lenm #eqf @\ 5a href="cic:/matita/basics/logic/False_ind.fix(0,1,1)"\ 6False_ind\ 5/a\ 6 @(\ 5a href="cic:/matita/basics/logic/absurd.def(2)"\ 6absurd\ 5/a\ 6 … eqf) @\ 5a href="cic:/matita/arithmetics/nat/lt_to_not_eq.def(7)"\ 6lt_to_not_eq\ 5/a\ 6
@\ 5a href="cic:/matita/arithmetics/nat/increasing_to_monotonic.def(4)"\ 6increasing_to_monotonic\ 5/a\ 6 //
|#nlenm #eqf @\ 5a href="cic:/matita/basics/logic/False_ind.fix(0,1,1)"\ 6False_ind\ 5/a\ 6 @(\ 5a href="cic:/matita/basics/logic/absurd.def(2)"\ 6absurd\ 5/a\ 6 … eqf) @\ 5a href="cic:/matita/basics/logic/sym_not_eq.def(4)"\ 6sym_not_eq\ 5/a\ 6
theorem lt_to_le_to_lt_times:
∀n,m,p,q:\ 5a href="cic:/matita/arithmetics/nat/nat.ind(1,0,0)"\ 6nat\ 5/a\ 6. n \ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6 m → p \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 q → \ 5a href="cic:/matita/arithmetics/nat/nat.con(0,1,0)"\ 6O\ 5/a\ 6 \ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6 q → n\ 5a title="natural times" href="cic:/fakeuri.def(1)"\ 6*\ 5/a\ 6p \ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6 m\ 5a title="natural times" href="cic:/fakeuri.def(1)"\ 6*\ 5/a\ 6q.
#n #m #p #q #ltnm #lepq #posq
-@(\ 5a href="cic:/matita/arithmetics/nat/le_to_lt_to_lt.def(4)"\ 6le_to_lt_to_lt\ 5/a\ 6 ? (n\ 5a title="natural times" href="cic:/fakeuri.def(1)"\ 6*\ 5/a\ 6q))
+@(\ 5a href="cic:/matita/arithmetics/nat/le_to_lt_to_lt.def(5)"\ 6le_to_lt_to_lt\ 5/a\ 6 ? (n\ 5a title="natural times" href="cic:/fakeuri.def(1)"\ 6*\ 5/a\ 6q))
[@\ 5a href="cic:/matita/arithmetics/nat/monotonic_le_times_r.def(8)"\ 6monotonic_le_times_r\ 5/a\ 6 //
- |@\ 5a href="cic:/matita/arithmetics/nat/monotonic_lt_times_l.def(9)"\ 6monotonic_lt_times_l\ 5/a\ 6 //
+ |@\ 5a href="cic:/matita/arithmetics/nat/monotonic_lt_times_l.def(10)"\ 6monotonic_lt_times_l\ 5/a\ 6 //
]
qed.
theorem lt_times:∀n,m,p,q:\ 5a href="cic:/matita/arithmetics/nat/nat.ind(1,0,0)"\ 6nat\ 5/a\ 6. n\ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6m → p\ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6q → n\ 5a title="natural times" href="cic:/fakeuri.def(1)"\ 6*\ 5/a\ 6p \ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6 m\ 5a title="natural times" href="cic:/fakeuri.def(1)"\ 6*\ 5/a\ 6q.
-#n #m #p #q #ltnm #ltpq @\ 5a href="cic:/matita/arithmetics/nat/lt_to_le_to_lt_times.def(10)"\ 6lt_to_le_to_lt_times\ 5/a\ 6/2/
+#n #m #p #q #ltnm #ltpq @\ 5a href="cic:/matita/arithmetics/nat/lt_to_le_to_lt_times.def(11)"\ 6lt_to_le_to_lt_times\ 5/a\ 6\ 5span style="text-decoration: underline;"\ 6 \ 5/span\ 6/2/
qed.
theorem lt_times_n_to_lt_l:
qed. *)
theorem eq_minus_S_pred: ∀n,m. n \ 5a title="natural minus" href="cic:/fakeuri.def(1)"\ 6-\ 5/a\ 6 (\ 5a href="cic:/matita/arithmetics/nat/nat.con(0,2,0)"\ 6S\ 5/a\ 6 m) \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 \ 5a href="cic:/matita/arithmetics/nat/pred.def(1)"\ 6pred\ 5/a\ 6(n \ 5a title="natural minus" href="cic:/fakeuri.def(1)"\ 6-\ 5/a\ 6m).
-@\ 5a href="cic:/matita/arithmetics/nat/nat_elim2.def(2)"\ 6nat_elim2\ 5/a\ 6 normalize // qed.
+@\ 5a href="cic:/matita/arithmetics/nat/nat_elim2.def(2)"\ 6nat_elim2\ 5/a\ 6 normalize //
+qed.
theorem plus_minus:
∀m,n,p:\ 5a href="cic:/matita/arithmetics/nat/nat.ind(1,0,0)"\ 6nat\ 5/a\ 6. m \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 n → (n\ 5a title="natural minus" href="cic:/fakeuri.def(1)"\ 6-\ 5/a\ 6m)\ 5a title="natural plus" href="cic:/fakeuri.def(1)"\ 6+\ 5/a\ 6p \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 (n\ 5a title="natural plus" href="cic:/fakeuri.def(1)"\ 6+\ 5/a\ 6p)\ 5a title="natural minus" href="cic:/fakeuri.def(1)"\ 6-\ 5/a\ 6m.
theorem minus_pred_pred : ∀n,m:\ 5a href="cic:/matita/arithmetics/nat/nat.ind(1,0,0)"\ 6nat\ 5/a\ 6. \ 5a href="cic:/matita/arithmetics/nat/nat.con(0,1,0)"\ 6O\ 5/a\ 6 \ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6 n → \ 5a href="cic:/matita/arithmetics/nat/nat.con(0,1,0)"\ 6O\ 5/a\ 6 \ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6 m →
\ 5a href="cic:/matita/arithmetics/nat/pred.def(1)"\ 6pred\ 5/a\ 6 n \ 5a title="natural minus" href="cic:/fakeuri.def(1)"\ 6-\ 5/a\ 6 \ 5a href="cic:/matita/arithmetics/nat/pred.def(1)"\ 6pred\ 5/a\ 6 m \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 n \ 5a title="natural minus" href="cic:/fakeuri.def(1)"\ 6-\ 5/a\ 6 m.
-#n #m #posn #posm @(\ 5a href="cic:/matita/arithmetics/nat/lt_O_n_elim.def(4)"\ 6lt_O_n_elim\ 5/a\ 6 n posn) @(\ 5a href="cic:/matita/arithmetics/nat/lt_O_n_elim.def(4)"\ 6lt_O_n_elim\ 5/a\ 6 m posm) //.
+#n #m #posn #posm @(\ 5a href="cic:/matita/arithmetics/nat/lt_O_n_elim.def(7)"\ 6lt_O_n_elim\ 5/a\ 6 n posn) @(\ 5a href="cic:/matita/arithmetics/nat/lt_O_n_elim.def(7)"\ 6lt_O_n_elim\ 5/a\ 6 m posm) //.
qed.
theorem le_minus_to_plus: ∀n,m,p. n\ 5a title="natural minus" href="cic:/fakeuri.def(1)"\ 6-\ 5/a\ 6m \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 p → n\ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 p\ 5a title="natural plus" href="cic:/fakeuri.def(1)"\ 6+\ 5/a\ 6m.
#n #m #p #lep @\ 5a href="cic:/matita/arithmetics/nat/transitive_le.def(3)"\ 6transitive_le\ 5/a\ 6
- [|@\ 5a href="cic:/matita/arithmetics/nat/le_plus_minus_m_m.def(6)"\ 6le_plus_minus_m_m\ 5/a\ 6 | @\ 5a href="cic:/matita/arithmetics/nat/monotonic_le_plus_l.def(6)"\ 6monotonic_le_plus_l\ 5/a\ 6 // ]
+ [|@\ 5a href="cic:/matita/arithmetics/nat/le_plus_minus_m_m.def(8)"\ 6le_plus_minus_m_m\ 5/a\ 6 | @\ 5a href="cic:/matita/arithmetics/nat/monotonic_le_plus_l.def(6)"\ 6monotonic_le_plus_l\ 5/a\ 6 // ]
qed.
theorem le_minus_to_plus_r: ∀a,b,c. c \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 b → a \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 b \ 5a title="natural minus" href="cic:/fakeuri.def(1)"\ 6-\ 5/a\ 6 c → a \ 5a title="natural plus" href="cic:/fakeuri.def(1)"\ 6+\ 5/a\ 6 c \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 b.
qed.
theorem lt_minus_to_plus_r: ∀a,b,c. a \ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6 b \ 5a title="natural minus" href="cic:/fakeuri.def(1)"\ 6-\ 5/a\ 6 c → a \ 5a title="natural plus" href="cic:/fakeuri.def(1)"\ 6+\ 5/a\ 6 c \ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6 b.
-#a #b #c #H @\ 5a href="cic:/matita/arithmetics/nat/not_le_to_lt.def(5)"\ 6not_le_to_lt\ 5/a\ 6 @(\ 5a href="cic:/matita/basics/logic/not_to_not.def(3)"\ 6not_to_not\ 5/a\ 6 … (\ 5a href="cic:/matita/arithmetics/nat/le_plus_to_minus.def(7)"\ 6le_plus_to_minus\ 5/a\ 6 …))
+#a #b #c #H @\ 5a href="cic:/matita/arithmetics/nat/not_le_to_lt.def(5)"\ 6not_le_to_lt\ 5/a\ 6 @(\ 5a href="cic:/matita/basics/logic/not_to_not.def(3)"\ 6not_to_not\ 5/a\ 6 … (\ 5a href="cic:/matita/arithmetics/nat/le_plus_to_minus.def(9)"\ 6le_plus_to_minus\ 5/a\ 6 …))
@\ 5a href="cic:/matita/arithmetics/nat/lt_to_not_le.def(7)"\ 6lt_to_not_le\ 5/a\ 6 //
qed.
theorem lt_plus_to_minus: ∀n,m,p. m \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 n → n \ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6 p\ 5a title="natural plus" href="cic:/fakeuri.def(1)"\ 6+\ 5/a\ 6m → n\ 5a title="natural minus" href="cic:/fakeuri.def(1)"\ 6-\ 5/a\ 6m \ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6 p.
-#n #m #p #lenm #H normalize <\ 5a href="cic:/matita/arithmetics/nat/minus_Sn_m.def(5)"\ 6minus_Sn_m\ 5/a\ 6 // @\ 5a href="cic:/matita/arithmetics/nat/le_plus_to_minus.def(7)"\ 6le_plus_to_minus\ 5/a\ 6 //
+#n #m #p #lenm #H normalize <\ 5a href="cic:/matita/arithmetics/nat/minus_Sn_m.def(5)"\ 6minus_Sn_m\ 5/a\ 6 // @\ 5a href="cic:/matita/arithmetics/nat/le_plus_to_minus.def(9)"\ 6le_plus_to_minus\ 5/a\ 6 //
qed.
theorem lt_plus_to_minus_r: ∀a,b,c. a \ 5a title="natural plus" href="cic:/fakeuri.def(1)"\ 6+\ 5/a\ 6 b \ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6 c → a \ 5a title="natural 'less than'" href="cic:/fakeuri.def(1)"\ 6<\ 5/a\ 6 c \ 5a title="natural minus" href="cic:/fakeuri.def(1)"\ 6-\ 5/a\ 6 b.
-#a #b #c #H @\ 5a href="cic:/matita/arithmetics/nat/le_plus_to_minus_r.def(7)"\ 6le_plus_to_minus_r\ 5/a\ 6 //
+#a #b #c #H @\ 5a href="cic:/matita/arithmetics/nat/le_plus_to_minus_r.def(9)"\ 6le_plus_to_minus_r\ 5/a\ 6 //
qed.
theorem monotonic_le_minus_r:
∀p,q,n:\ 5a href="cic:/matita/arithmetics/nat/nat.ind(1,0,0)"\ 6nat\ 5/a\ 6. q \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 p → n\ 5a title="natural minus" href="cic:/fakeuri.def(1)"\ 6-\ 5/a\ 6p \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 n\ 5a title="natural minus" href="cic:/fakeuri.def(1)"\ 6-\ 5/a\ 6q.
-#p #q #n #lepq @\ 5a href="cic:/matita/arithmetics/nat/le_plus_to_minus.def(7)"\ 6le_plus_to_minus\ 5/a\ 6
-@(\ 5a href="cic:/matita/arithmetics/nat/transitive_le.def(3)"\ 6transitive_le\ 5/a\ 6 … (\ 5a href="cic:/matita/arithmetics/nat/le_plus_minus_m_m.def(6)"\ 6le_plus_minus_m_m\ 5/a\ 6 ? q)) /2/
+#p #q #n #lepq @\ 5a href="cic:/matita/arithmetics/nat/le_plus_to_minus.def(9)"\ 6le_plus_to_minus\ 5/a\ 6
+@(\ 5a href="cic:/matita/arithmetics/nat/transitive_le.def(3)"\ 6transitive_le\ 5/a\ 6 … (\ 5a href="cic:/matita/arithmetics/nat/le_plus_minus_m_m.def(8)"\ 6le_plus_minus_m_m\ 5/a\ 6 ? q)) /2/
qed.
theorem eq_minus_O: ∀n,m:\ 5a href="cic:/matita/arithmetics/nat/nat.ind(1,0,0)"\ 6nat\ 5/a\ 6.
theorem distributive_times_minus: \ 5a href="cic:/matita/basics/relations/distributive.def(1)"\ 6distributive\ 5/a\ 6 ? \ 5a href="cic:/matita/arithmetics/nat/times.fix(0,0,2)"\ 6times\ 5/a\ 6 \ 5a href="cic:/matita/arithmetics/nat/minus.fix(0,0,1)"\ 6minus\ 5/a\ 6.
#a #b #c
(cases (\ 5a href="cic:/matita/arithmetics/nat/decidable_lt.def(7)"\ 6decidable_lt\ 5/a\ 6 b c)) #Hbc
- [> \ 5a href="cic:/matita/arithmetics/nat/eq_minus_O.def(9)"\ 6eq_minus_O\ 5/a\ 6 /2/ >\ 5a href="cic:/matita/arithmetics/nat/eq_minus_O.def(9)"\ 6eq_minus_O\ 5/a\ 6 //
+ [> \ 5a href="cic:/matita/arithmetics/nat/eq_minus_O.def(11)"\ 6eq_minus_O\ 5/a\ 6 /2/ >\ 5a href="cic:/matita/arithmetics/nat/eq_minus_O.def(11)"\ 6eq_minus_O\ 5/a\ 6 //
@\ 5a href="cic:/matita/arithmetics/nat/monotonic_le_times_r.def(8)"\ 6monotonic_le_times_r\ 5/a\ 6 /2/
|@\ 5a href="cic:/matita/basics/logic/sym_eq.def(2)"\ 6sym_eq\ 5/a\ 6 (applyS \ 5a href="cic:/matita/arithmetics/nat/plus_to_minus.def(7)"\ 6plus_to_minus\ 5/a\ 6) <\ 5a href="cic:/matita/arithmetics/nat/distributive_times_plus.def(7)"\ 6distributive_times_plus\ 5/a\ 6
@\ 5a href="cic:/matita/basics/logic/eq_f.def(3)"\ 6eq_f\ 5/a\ 6 (applyS \ 5a href="cic:/matita/arithmetics/nat/plus_minus_m_m.def(7)"\ 6plus_minus_m_m\ 5/a\ 6) /2/
[@\ 5a href="cic:/matita/arithmetics/nat/plus_to_minus.def(7)"\ 6plus_to_minus\ 5/a\ 6 @\ 5a href="cic:/matita/arithmetics/nat/plus_to_minus.def(7)"\ 6plus_to_minus\ 5/a\ 6 <\ 5a href="cic:/matita/arithmetics/nat/associative_plus.def(4)"\ 6associative_plus\ 5/a\ 6
@\ 5a href="cic:/matita/arithmetics/nat/minus_to_plus.def(8)"\ 6minus_to_plus\ 5/a\ 6 //
|cut (n \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 m\ 5a title="natural plus" href="cic:/fakeuri.def(1)"\ 6+\ 5/a\ 6p) [@(\ 5a href="cic:/matita/arithmetics/nat/transitive_le.def(3)"\ 6transitive_le\ 5/a\ 6 … (\ 5a href="cic:/matita/arithmetics/nat/le_n_Sn.def(1)"\ 6le_n_Sn\ 5/a\ 6 …)) @\ 5a href="cic:/matita/arithmetics/nat/not_le_to_lt.def(5)"\ 6not_le_to_lt\ 5/a\ 6 //]
- #H >\ 5a href="cic:/matita/arithmetics/nat/eq_minus_O.def(9)"\ 6eq_minus_O\ 5/a\ 6 /2/ >\ 5a href="cic:/matita/arithmetics/nat/eq_minus_O.def(9)"\ 6eq_minus_O\ 5/a\ 6 //
+ #H >\ 5a href="cic:/matita/arithmetics/nat/eq_minus_O.def(11)"\ 6eq_minus_O\ 5/a\ 6 /2/ >\ 5a href="cic:/matita/arithmetics/nat/eq_minus_O.def(11)"\ 6eq_minus_O\ 5/a\ 6 //
]
qed.
lemma to_max: ∀i,n,m. n \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 i → m \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 i → \ 5a href="cic:/matita/arithmetics/nat/max.def(2)"\ 6max\ 5/a\ 6 n m \ 5a title="natural 'less or equal to'" href="cic:/fakeuri.def(1)"\ 6≤\ 5/a\ 6 i.
#i #n #m #leni #lemi normalize (cases (\ 5a href="cic:/matita/arithmetics/nat/leb.fix(0,0,1)"\ 6leb\ 5/a\ 6 n m))
-normalize // qed.
+normalize // qed.
\ No newline at end of file
definition relation : Type[0] → Type[0]
≝ λA.A→A→Prop.
-definition reflexive: ∀A.∀R :relation A.Prop
+definition reflexive: ∀A.∀R :\ 5a href="cic:/matita/basics/relations/relation.def(1)"\ 6relation\ 5/a\ 6 A.Prop
≝ λA.λR.∀x:A.R x x.
-definition symmetric: ∀A.∀R: relation A.Prop
+definition symmetric: ∀A.∀R: \ 5a href="cic:/matita/basics/relations/relation.def(1)"\ 6relation\ 5/a\ 6 A.Prop
≝ λA.λR.∀x,y:A.R x y → R y x.
-definition transitive: ∀A.∀R:relation A.Prop
+definition transitive: ∀A.∀R:\ 5a href="cic:/matita/basics/relations/relation.def(1)"\ 6relation\ 5/a\ 6 A.Prop
≝ λA.λR.∀x,y,z:A.R x y → R y z → R x z.
-definition irreflexive: ∀A.∀R:relation A.Prop
-≝ λA.λR.∀x:A.¬(R x x).
+definition irreflexive: ∀A.∀R:\ 5a href="cic:/matita/basics/relations/relation.def(1)"\ 6relation\ 5/a\ 6 A.Prop
+≝ λA.λR.∀x:A.\ 5a title="logical not" href="cic:/fakeuri.def(1)"\ 6¬\ 5/a\ 6(R x x).
-definition cotransitive: ∀A.∀R:relation A.Prop
-≝ λA.λR.∀x,y:A.R x y → ∀z:A. R x z ∨ R z y.
+definition cotransitive: ∀A.∀R:\ 5a href="cic:/matita/basics/relations/relation.def(1)"\ 6relation\ 5/a\ 6 A.Prop
+≝ λA.λR.∀x,y:A.R x y → ∀z:A. R x z \ 5a title="logical or" href="cic:/fakeuri.def(1)"\ 6∨\ 5/a\ 6 R z y.
-definition tight_apart: ∀A.∀eq,ap:relation A.Prop
-≝ λA.λeq,ap.∀x,y:A. (¬(ap x y) → eq x y) ∧
-(eq x y → ¬(ap x y)).
+definition tight_apart: ∀A.∀eq,ap:\ 5a href="cic:/matita/basics/relations/relation.def(1)"\ 6relation\ 5/a\ 6 A.Prop
+≝ λA.λeq,ap.∀x,y:A. (\ 5a title="logical not" href="cic:/fakeuri.def(1)"\ 6¬\ 5/a\ 6(ap x y) → eq x y) \ 5a title="logical and" href="cic:/fakeuri.def(1)"\ 6∧\ 5/a\ 6
+(eq x y → \ 5a title="logical not" href="cic:/fakeuri.def(1)"\ 6¬\ 5/a\ 6(ap x y)).
-definition antisymmetric: ∀A.∀R:relation A.Prop
-≝ λA.λR.∀x,y:A. R x y → ¬(R y x).
+definition antisymmetric: ∀A.∀R:\ 5a href="cic:/matita/basics/relations/relation.def(1)"\ 6relation\ 5/a\ 6 A.Prop
+≝ λA.λR.∀x,y:A. R x y → \ 5a title="logical not" href="cic:/fakeuri.def(1)"\ 6¬\ 5/a\ 6(R y x).
(********** functions **********)
interpretation "function composition" 'compose f g = (compose ? ? ? f g).
definition injective: ∀A,B:Type[0].∀ f:A→B.Prop
-≝ λA,B.λf.∀x,y:A.f x = f y → x=y.
+≝ λA,B.λf.∀x,y:A.f x \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 f y → x\ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6y.
definition surjective: ∀A,B:Type[0].∀f:A→B.Prop
-≝λA,B.λf.∀z:B.∃x:A.z = f x.
+≝λA,B.λf.∀z:B.\ 5a title="exists" href="cic:/fakeuri.def(1)"\ 6∃\ 5/a\ 6x:A.z \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 f x.
definition commutative: ∀A:Type[0].∀f:A→A→A.Prop
-≝ λA.λf.∀x,y.f x y = f y x.
+≝ λA.λf.∀x,y.f x y \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 f y x.
definition commutative2: ∀A,B:Type[0].∀f:A→A→B.Prop
-≝ λA,B.λf.∀x,y.f x y = f y x.
+≝ λA,B.λf.∀x,y.f x y \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 f y x.
definition associative: ∀A:Type[0].∀f:A→A→A.Prop
-≝ λA.λf.∀x,y,z.f (f x y) z = f x (f y z).
+≝ λA.λf.∀x,y,z.f (f x y) z \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 f x (f y z).
(* functions and relations *)
definition monotonic : ∀A:Type[0].∀R:A→A→Prop.
(* functions and functions *)
definition distributive: ∀A:Type[0].∀f,g:A→A→A.Prop
-≝ λA.λf,g.∀x,y,z:A. f x (g y z) = g (f x y) (f x z).
+≝ λA.λf,g.∀x,y,z:A. f x (g y z) \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 g (f x y) (f x z).
definition distributive2: ∀A,B:Type[0].∀f:A→B→B.∀g:B→B→B.Prop
-≝ λA,B.λf,g.∀x:A.∀y,z:B. f x (g y z) = g (f x y) (f x z).
+≝ λA,B.λf,g.∀x:A.∀y,z:B. f x (g y z) \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 g (f x y) (f x z).
lemma injective_compose : ∀A,B,C,f,g.
-injective A B f → injective B C g → injective A C (λx.g (f x)).
+\ 5a href="cic:/matita/basics/relations/injective.def(1)"\ 6injective\ 5/a\ 6 A B f → \ 5a href="cic:/matita/basics/relations/injective.def(1)"\ 6injective\ 5/a\ 6 B C g → \ 5a href="cic:/matita/basics/relations/injective.def(1)"\ 6injective\ 5/a\ 6 A C (λx.g (f x)).
/3/; qed.
(* extensional equality *)
definition exteqP: ∀A:Type[0].∀P,Q:A→Prop.Prop ≝
-λA.λP,Q.∀a.iff (P a) (Q a).
+λA.λP,Q.∀a.\ 5a href="cic:/matita/basics/logic/iff.def(1)"\ 6iff\ 5/a\ 6 (P a) (Q a).
definition exteqR: ∀A,B:Type[0].∀R,S:A→B→Prop.Prop ≝
-λA,B.λR,S.∀a.∀b.iff (R a b) (S a b).
+λA,B.λR,S.∀a.∀b.\ 5a href="cic:/matita/basics/logic/iff.def(1)"\ 6iff\ 5/a\ 6 (R a b) (S a b).
definition exteqF: ∀A,B:Type[0].∀f,g:A→B.Prop ≝
-λA,B.λf,g.∀a.f a = g a.
+λA,B.λf,g.∀a.f a \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 g a.
notation " x \eqP y " non associative with precedence 45
for @{'eqP A $x $y}.
for @{'eqF ? ? f g}.
interpretation "functional extentional equality"
-'eqF A B f g = (exteqF A B f g).
-
+'eqF A B f g = (exteqF A B f g).
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