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15 (* This file was automatically generated: do not edit *********************)
17 set "baseuri" "cic:/matita/CoRN-Decl/model/structures/Qpossec".
19 (* $Id: Qpossec.v,v 1.5 2004/04/06 15:46:05 lcf Exp $ *)
21 (*#* printing Qpos $\mathbb{Q}^{+}$ #Q<SUP>+</SUP># *)
32 We will prove some lemmas concerning rationals bigger than 0.
35 One, two and four are all bigger than zero.
38 inline cic:/CoRN/model/structures/Qpossec/pos_QONE.con.
40 inline cic:/CoRN/model/structures/Qpossec/pos_QTWO.con.
42 inline cic:/CoRN/model/structures/Qpossec/pos_QFOUR.con.
44 (*#* A positive rational is not zero.
47 inline cic:/CoRN/model/structures/Qpossec/pos_imp_nonzero.con.
49 (*#* ***Multiplication
50 The product of two positive rationals is again positive.
53 inline cic:/CoRN/model/structures/Qpossec/Qmult_pres_pos0.con.
56 The inverse of a positive rational is again positive.
59 inline cic:/CoRN/model/structures/Qpossec/inv_pres_pos0.con.
61 (*#* ***Special multiplication
62 Now we will investigate the function $(x,y) \mapsto xy/2$#(x,y)
63 ↦ xy/2#. We will see that its unit is 2. Its inverse map is $x
64 \mapsto 4/x$ #x ↦ 4/x#.
67 inline cic:/CoRN/model/structures/Qpossec/QTWOpos_is_rht_unit0.con.
69 inline cic:/CoRN/model/structures/Qpossec/QTWOpos_is_left_unit0.con.
71 inline cic:/CoRN/model/structures/Qpossec/multdiv2_is_inv.con.