src/HOL/Groups.thy
changeset 70347 e5cd5471c18a
parent 69605 a96320074298
child 70490 c42a0a0a9a8d
equal deleted inserted replaced
70346:408e15cbd2a6 70347:e5cd5471c18a
    13 begin
    13 begin
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    14 
    15 subsection \<open>Dynamic facts\<close>
    15 subsection \<open>Dynamic facts\<close>
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    16 
    17 named_theorems ac_simps "associativity and commutativity simplification rules"
    17 named_theorems ac_simps "associativity and commutativity simplification rules"
    18   and algebra_simps "algebra simplification rules"
    18   and algebra_simps "algebra simplification rules for rings"
    19   and field_simps "algebra simplification rules for fields"
    19   and field_simps "algebra simplification rules for fields"
       
    20   and sign_simps "algebra simplification rules for comparision with zero"
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    21 
    21 text \<open>
    22 text \<open>
    22   The rewrites accumulated in \<open>algebra_simps\<close> deal with the classical
    23   The rewrites accumulated in \<open>algebra_simps\<close> deal with the classical
    23   algebraic structures of groups, rings and family. They simplify terms by
    24   algebraic structures of groups, rings and family. They simplify terms by
    24   multiplying everything out (in case of a ring) and bringing sums and
    25   multiplying everything out (in case of a ring) and bringing sums and
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    31 
    31   Facts in \<open>field_simps\<close> multiply with denominators in (in)equations if they
    32   Facts in \<open>field_simps\<close> multiply with denominators in (in)equations if they
    32   can be proved to be non-zero (for equations) or positive/negative (for
    33   can be proved to be non-zero (for equations) or positive/negative (for
    33   inequalities). Can be too aggressive and is therefore separate from the more
    34   inequalities). Can be too aggressive and is therefore separate from the more
    34   benign \<open>algebra_simps\<close>.
    35   benign \<open>algebra_simps\<close>.
       
    36 
       
    37   Lemmas \<open>sign_simps\<close> is a first attempt to automate proofs
       
    38   of positivity/negativity needed for \<open>field_simps\<close>. Have not added \<open>sign_simps\<close> to \<open>field_simps\<close>
       
    39   because the former can lead to case explosions.
    35 \<close>
    40 \<close>
    36 
    41 
    37 
    42 
    38 subsection \<open>Abstract structures\<close>
    43 subsection \<open>Abstract structures\<close>
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    44