diff -r 181a70d7b525 -r f2c98b8c0c5c src/HOL/Word/Size.thy --- a/src/HOL/Word/Size.thy Wed Jun 30 21:29:58 2010 -0700 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,71 +0,0 @@ -(* - Author: John Matthews, Galois Connections, Inc., copyright 2006 - - A typeclass for parameterizing types by size. - Used primarily to parameterize machine word sizes. -*) - -header "The len classes" - -theory Size -imports Numeral_Type -begin - -text {* - The aim of this is to allow any type as index type, but to provide a - default instantiation for numeral types. This independence requires - some duplication with the definitions in @{text "Numeral_Type"}. -*} - -class len0 = - fixes len_of :: "'a itself \ nat" - -text {* - Some theorems are only true on words with length greater 0. -*} - -class len = len0 + - assumes len_gt_0 [iff]: "0 < len_of TYPE ('a)" - -instantiation num0 and num1 :: len0 -begin - -definition - len_num0: "len_of (x::num0 itself) = 0" - -definition - len_num1: "len_of (x::num1 itself) = 1" - -instance .. - -end - -instantiation bit0 and bit1 :: (len0) len0 -begin - -definition - len_bit0: "len_of (x::'a::len0 bit0 itself) = 2 * len_of TYPE ('a)" - -definition - len_bit1: "len_of (x::'a::len0 bit1 itself) = 2 * len_of TYPE ('a) + 1" - -instance .. - -end - -lemmas len_of_numeral_defs [simp] = len_num0 len_num1 len_bit0 len_bit1 - -instance num1 :: len by (intro_classes) simp -instance bit0 :: (len) len by (intro_classes) simp -instance bit1 :: (len0) len by (intro_classes) simp - --- "Examples:" -lemma "len_of TYPE(17) = 17" by simp -lemma "len_of TYPE(0) = 0" by simp - --- "not simplified:" -lemma "len_of TYPE('a::len0) = x" - oops - -end -