doc-src/TutorialI/Sets/Functions.thy
changeset 10849 de981d0037ed
parent 10839 1f93f5a27de6
child 10983 59961d32b1ae
equal deleted inserted replaced
10848:7b3ee4695fe6 10849:de981d0037ed
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   117 
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   119 text{*
   119 text{*
   120 illustrates Union as well as image
   120 illustrates Union as well as image
   121 *}
   121 *}
       
   122 
   122 lemma "f`A \<union> g`A = (\<Union>x\<in>A. {f x, g x})"
   123 lemma "f`A \<union> g`A = (\<Union>x\<in>A. {f x, g x})"
   123   apply (blast)
   124 by blast
   124   done
       
   125 
   125 
   126 lemma "f ` {(x,y). P x y} = {f(x,y) | x y. P x y}"
   126 lemma "f ` {(x,y). P x y} = {f(x,y) | x y. P x y}"
   127   apply (blast)
   127 by blast
   128   done
       
   129 
   128 
   130 text{*actually a macro!*}
   129 text{*actually a macro!*}
   131 
   130 
   132 lemma "range f = f`UNIV"
   131 lemma "range f = f`UNIV"
   133   apply (blast)
   132 by blast
   134   done
       
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   133 
   136 
   134 
   137 text{*
   135 text{*
   138 inverse image
   136 inverse image
   139 *}
   137 *}