src/HOL/Number_Theory/Primes.thy
changeset 62481 b5d8e57826df
parent 62429 25271ff79171
child 63534 523b488b15c9
equal deleted inserted replaced
62480:f2e8984adef7 62481:b5d8e57826df
    94 lemma prime_dvd_mult_eq_int [simp]:
    94 lemma prime_dvd_mult_eq_int [simp]:
    95   fixes n::int
    95   fixes n::int
    96   shows "prime p \<Longrightarrow> p dvd m * n = (p dvd m \<or> p dvd n)"
    96   shows "prime p \<Longrightarrow> p dvd m * n = (p dvd m \<or> p dvd n)"
    97   by (rule iffI, rule prime_dvd_mult_int, auto)
    97   by (rule iffI, rule prime_dvd_mult_int, auto)
    98 
    98 
    99 lemma not_prime_eq_prod_nat: "(n::nat) > 1 \<Longrightarrow> ~ prime n \<Longrightarrow>
    99 lemma not_prime_eq_prod_nat:
   100     EX m k. n = m * k & 1 < m & m < n & 1 < k & k < n"
   100   "1 < n \<Longrightarrow> \<not> prime n \<Longrightarrow>
   101   unfolding prime_def dvd_def apply auto
   101     \<exists>m k. n = m * k \<and> 1 < m \<and> m < n \<and> 1 < k \<and> k < n"
   102   by (metis mult.commute linorder_neq_iff linorder_not_le mult_1
   102   unfolding prime_def dvd_def apply (auto simp add: ac_simps)
   103       n_less_n_mult_m one_le_mult_iff less_imp_le_nat)
   103   by (metis Suc_lessD Suc_lessI n_less_m_mult_n n_less_n_mult_m nat_0_less_mult_iff)
   104 
   104 
   105 lemma prime_dvd_power_nat: "prime p \<Longrightarrow> p dvd x^n \<Longrightarrow> p dvd x"
   105 lemma prime_dvd_power_nat: "prime p \<Longrightarrow> p dvd x^n \<Longrightarrow> p dvd x"
   106   by (induct n) auto
   106   by (induct n) auto
   107 
   107 
   108 lemma prime_dvd_power_int:
   108 lemma prime_dvd_power_int: