factor_1 Theory
Introduces the theory of divisibility in cancellation monoids,
and builds up to theorem characterizing when unique factorizations
exist and are unique.
The theory here is developed constructively. Some theorems
computable content is `useful': e.g. mfact_exists. An instantiation
of this theorem is posint_is_ufm, which has as extract, a theorem
to compute prime factorisations. Other theorems have computational
content which is for most purposes uninteresting. e.g. look at theorem
unique_mfact.
The theorem unique_mfact nicely demonstrates rewriting with
equivalence relations of differing strengths: e.g. permr and permr_upto.
Summary of Definitions
Typed Definitions
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mdivides
*2
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rev_mdivides
*1
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munit
*1
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mpdivides
*1
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massoc
*1
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mprime
*1
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mprime_ty
*1
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mreducible
*1
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matomic
*1
-
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matom_ty
*1
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permr_massoc
*1
-
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uni_sat_upto
*1
-
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exists_uni_upto
*1
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permr_massoc_rel
*1
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is_ufm
*1
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posint_mul_mon
*11
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Main Theorems
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mdivides_id
*3
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mdivides_refl
*3
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mdivides_trans
*6
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mdivides_preorder
*4
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mdivides_cancel
*6
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munit_char
*4
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munit_of_op
*9
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non_munit_diff_imp_mpdivides
*10
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mdivides_weakening
*2
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massoc_equiv_rel
*4
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massoc_weakening
*6
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massoc_inversion
*5
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massoc_transitivity
*5
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grp_op_ap2_functionality_wrt_massoc
*5
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grp_op_ap2_functionality_wrt_mdivides
*4
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massoc_functionality_wrt_massoc
*3
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massoc_cancel
*3
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massoc_imp_unit_diff
*14
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sq_stable__mprime
*5
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mproper_div_cond
*9
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mreducible_elim
*16
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mdivisor_of_atom_is_assoc
*11
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mcomp_imp_not_unit
*15
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mprime_imp_matomic
*20
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mprime_divs_list_el
*17
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permr_massoc_weakening
*4
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permr_massoc_functionality
*5
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cons_functionality_wrt_permr_massoc
*4
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mfact_exists
*18
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mfact_exists_a
*7
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unique_mfact
*34
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exists_uni_upto_char
*5
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ufm_char
*12
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posint_cancel
*7
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posint_munit_elim
*5
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posint_well_fnd
*11
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posint_reduc_dec
*12
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posint_unit_dec
*2
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posint_div_dec
*1
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posint_atom_imp_prime
*1
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posint_fact_exists
*30
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posint_is_ufm
*6
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Listing
Last modified February 24th, 1995
Paul Jackson /
jackson@cs.cornell.edu