author | haftmann |
Fri, 07 Dec 2007 15:07:59 +0100 | |
changeset 25571 | c9e39eafc7a0 |
parent 25349 | 0d46bea01741 |
child 25762 | c03e9d04b3e4 |
permissions | -rw-r--r-- |
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(* |
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ID: $Id$ |
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Author: Jeremy Dawson and Gerwin Klein, NICTA |
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Basic definition of word type and basic theorems following from |
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the definition of the word type |
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*) |
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header {* Definition of Word Type *} |
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theory WordDefinition imports Size BinBoolList TdThs begin |
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typedef (open word) 'a word |
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= "{(0::int) ..< 2^len_of TYPE('a::len0)}" by auto |
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instance word :: (len0) number .. |
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instance word :: (type) minus .. |
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instance word :: (type) plus .. |
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instance word :: (type) one .. |
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instance word :: (type) zero .. |
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instance word :: (type) times .. |
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instance word :: (type) Divides.div .. |
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instance word :: (type) power .. |
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instance word :: (type) ord .. |
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instance word :: (type) size .. |
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instance word :: (type) inverse .. |
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instance word :: (type) bit .. |
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subsection "Type conversions and casting" |
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constdefs |
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-- {* representation of words using unsigned or signed bins, |
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only difference in these is the type class *} |
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word_of_int :: "int => 'a :: len0 word" |
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"word_of_int w == Abs_word (bintrunc (len_of TYPE ('a)) w)" |
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-- {* uint and sint cast a word to an integer, |
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uint treats the word as unsigned, |
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sint treats the most-significant-bit as a sign bit *} |
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uint :: "'a :: len0 word => int" |
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"uint w == Rep_word w" |
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sint :: "'a :: len word => int" |
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sint_uint: "sint w == sbintrunc (len_of TYPE ('a) - 1) (uint w)" |
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unat :: "'a :: len0 word => nat" |
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"unat w == nat (uint w)" |
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-- "the sets of integers representing the words" |
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uints :: "nat => int set" |
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"uints n == range (bintrunc n)" |
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sints :: "nat => int set" |
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"sints n == range (sbintrunc (n - 1))" |
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unats :: "nat => nat set" |
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"unats n == {i. i < 2 ^ n}" |
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norm_sint :: "nat => int => int" |
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"norm_sint n w == (w + 2 ^ (n - 1)) mod 2 ^ n - 2 ^ (n - 1)" |
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-- "cast a word to a different length" |
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scast :: "'a :: len word => 'b :: len word" |
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"scast w == word_of_int (sint w)" |
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ucast :: "'a :: len0 word => 'b :: len0 word" |
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"ucast w == word_of_int (uint w)" |
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-- "whether a cast (or other) function is to a longer or shorter length" |
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source_size :: "('a :: len0 word => 'b) => nat" |
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"source_size c == let arb = arbitrary ; x = c arb in size arb" |
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target_size :: "('a => 'b :: len0 word) => nat" |
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"target_size c == size (c arbitrary)" |
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is_up :: "('a :: len0 word => 'b :: len0 word) => bool" |
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"is_up c == source_size c <= target_size c" |
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is_down :: "('a :: len0 word => 'b :: len0 word) => bool" |
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"is_down c == target_size c <= source_size c" |
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constdefs |
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of_bl :: "bool list => 'a :: len0 word" |
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"of_bl bl == word_of_int (bl_to_bin bl)" |
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to_bl :: "'a :: len0 word => bool list" |
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"to_bl w == |
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bin_to_bl (len_of TYPE ('a)) (uint w)" |
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word_reverse :: "'a :: len0 word => 'a word" |
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"word_reverse w == of_bl (rev (to_bl w))" |
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defs (overloaded) |
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word_size: "size (w :: 'a :: len0 word) == len_of TYPE('a)" |
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word_number_of_def: "number_of w == word_of_int w" |
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constdefs |
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word_int_case :: "(int => 'b) => ('a :: len0 word) => 'b" |
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"word_int_case f w == f (uint w)" |
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syntax |
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of_int :: "int => 'a" |
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translations |
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"case x of of_int y => b" == "word_int_case (%y. b) x" |
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subsection "Arithmetic operations" |
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defs (overloaded) |
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word_1_wi: "(1 :: ('a :: len0) word) == word_of_int 1" |
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word_0_wi: "(0 :: ('a :: len0) word) == word_of_int 0" |
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word_le_def: "a <= b == uint a <= uint b" |
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word_less_def: "x < y == x <= y & x ~= (y :: 'a :: len0 word)" |
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constdefs |
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word_succ :: "'a :: len0 word => 'a word" |
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"word_succ a == word_of_int (Numeral.succ (uint a))" |
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word_pred :: "'a :: len0 word => 'a word" |
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"word_pred a == word_of_int (Numeral.pred (uint a))" |
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udvd :: "'a::len word => 'a::len word => bool" (infixl "udvd" 50) |
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"a udvd b == EX n>=0. uint b = n * uint a" |
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word_sle :: "'a :: len word => 'a word => bool" ("(_/ <=s _)" [50, 51] 50) |
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"a <=s b == sint a <= sint b" |
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word_sless :: "'a :: len word => 'a word => bool" ("(_/ <s _)" [50, 51] 50) |
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"(x <s y) == (x <=s y & x ~= y)" |
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consts |
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word_power :: "'a :: len0 word => nat => 'a word" |
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primrec |
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"word_power a 0 = 1" |
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"word_power a (Suc n) = a * word_power a n" |
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defs (overloaded) |
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word_pow: "power == word_power" |
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word_add_def: "a + b == word_of_int (uint a + uint b)" |
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word_sub_wi: "a - b == word_of_int (uint a - uint b)" |
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word_minus_def: "- a == word_of_int (- uint a)" |
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word_mult_def: "a * b == word_of_int (uint a * uint b)" |
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word_div_def: "a div b == word_of_int (uint a div uint b)" |
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word_mod_def: "a mod b == word_of_int (uint a mod uint b)" |
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subsection "Bit-wise operations" |
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defs (overloaded) |
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word_and_def: |
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"(a::'a::len0 word) AND b == word_of_int (uint a AND uint b)" |
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word_or_def: |
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"(a::'a::len0 word) OR b == word_of_int (uint a OR uint b)" |
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word_xor_def: |
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"(a::'a::len0 word) XOR b == word_of_int (uint a XOR uint b)" |
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word_not_def: |
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"NOT (a::'a::len0 word) == word_of_int (NOT (uint a))" |
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word_test_bit_def: |
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"test_bit (a::'a::len0 word) == bin_nth (uint a)" |
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word_set_bit_def: |
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"set_bit (a::'a::len0 word) n x == |
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word_of_int (bin_sc n (If x bit.B1 bit.B0) (uint a))" |
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word_set_bits_def: |
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"(BITS n. f n)::'a::len0 word == of_bl (bl_of_nth (len_of TYPE ('a)) f)" |
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word_lsb_def: |
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"lsb (a::'a::len0 word) == bin_last (uint a) = bit.B1" |
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word_msb_def: |
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"msb (a::'a::len word) == bin_sign (sint a) = Numeral.Min" |
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constdefs |
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setBit :: "'a :: len0 word => nat => 'a word" |
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"setBit w n == set_bit w n True" |
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clearBit :: "'a :: len0 word => nat => 'a word" |
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"clearBit w n == set_bit w n False" |
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subsection "Shift operations" |
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constdefs |
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shiftl1 :: "'a :: len0 word => 'a word" |
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"shiftl1 w == word_of_int (uint w BIT bit.B0)" |
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-- "shift right as unsigned or as signed, ie logical or arithmetic" |
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shiftr1 :: "'a :: len0 word => 'a word" |
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"shiftr1 w == word_of_int (bin_rest (uint w))" |
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sshiftr1 :: "'a :: len word => 'a word" |
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"sshiftr1 w == word_of_int (bin_rest (sint w))" |
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bshiftr1 :: "bool => 'a :: len word => 'a word" |
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"bshiftr1 b w == of_bl (b # butlast (to_bl w))" |
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sshiftr :: "'a :: len word => nat => 'a word" (infixl ">>>" 55) |
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"w >>> n == (sshiftr1 ^ n) w" |
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mask :: "nat => 'a::len word" |
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"mask n == (1 << n) - 1" |
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revcast :: "'a :: len0 word => 'b :: len0 word" |
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"revcast w == of_bl (takefill False (len_of TYPE('b)) (to_bl w))" |
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slice1 :: "nat => 'a :: len0 word => 'b :: len0 word" |
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"slice1 n w == of_bl (takefill False n (to_bl w))" |
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slice :: "nat => 'a :: len0 word => 'b :: len0 word" |
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"slice n w == slice1 (size w - n) w" |
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defs (overloaded) |
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shiftl_def: "(w::'a::len0 word) << n == (shiftl1 ^ n) w" |
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shiftr_def: "(w::'a::len0 word) >> n == (shiftr1 ^ n) w" |
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subsection "Rotation" |
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constdefs |
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rotater1 :: "'a list => 'a list" |
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"rotater1 ys == |
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case ys of [] => [] | x # xs => last ys # butlast ys" |
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rotater :: "nat => 'a list => 'a list" |
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"rotater n == rotater1 ^ n" |
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word_rotr :: "nat => 'a :: len0 word => 'a :: len0 word" |
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"word_rotr n w == of_bl (rotater n (to_bl w))" |
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word_rotl :: "nat => 'a :: len0 word => 'a :: len0 word" |
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"word_rotl n w == of_bl (rotate n (to_bl w))" |
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word_roti :: "int => 'a :: len0 word => 'a :: len0 word" |
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"word_roti i w == if i >= 0 then word_rotr (nat i) w |
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else word_rotl (nat (- i)) w" |
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subsection "Split and cat operations" |
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constdefs |
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word_cat :: "'a :: len0 word => 'b :: len0 word => 'c :: len0 word" |
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"word_cat a b == word_of_int (bin_cat (uint a) (len_of TYPE ('b)) (uint b))" |
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word_split :: "'a :: len0 word => ('b :: len0 word) * ('c :: len0 word)" |
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"word_split a == |
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case bin_split (len_of TYPE ('c)) (uint a) of |
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(u, v) => (word_of_int u, word_of_int v)" |
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word_rcat :: "'a :: len0 word list => 'b :: len0 word" |
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"word_rcat ws == |
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word_of_int (bin_rcat (len_of TYPE ('a)) (map uint ws))" |
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word_rsplit :: "'a :: len0 word => 'b :: len word list" |
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"word_rsplit w == |
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map word_of_int (bin_rsplit (len_of TYPE ('b)) (len_of TYPE ('a), uint w))" |
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constdefs |
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-- "Largest representable machine integer." |
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max_word :: "'a::len word" |
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"max_word \<equiv> word_of_int (2^len_of TYPE('a) - 1)" |
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consts |
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of_bool :: "bool \<Rightarrow> 'a::len word" |
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primrec |
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"of_bool False = 0" |
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"of_bool True = 1" |
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lemmas of_nth_def = word_set_bits_def |
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lemmas word_size_gt_0 [iff] = |
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xtr1 [OF word_size [THEN meta_eq_to_obj_eq] len_gt_0, standard] |
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lemmas lens_gt_0 = word_size_gt_0 len_gt_0 |
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lemmas lens_not_0 [iff] = lens_gt_0 [THEN gr_implies_not0, standard] |
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lemma uints_num: "uints n = {i. 0 \<le> i \<and> i < 2 ^ n}" |
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by (simp add: uints_def range_bintrunc) |
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lemma sints_num: "sints n = {i. - (2 ^ (n - 1)) \<le> i \<and> i < 2 ^ (n - 1)}" |
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by (simp add: sints_def range_sbintrunc) |
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lemmas atLeastLessThan_alt = atLeastLessThan_def [unfolded |
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atLeast_def lessThan_def Collect_conj_eq [symmetric]] |
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lemma mod_in_reps: "m > 0 ==> y mod m : {0::int ..< m}" |
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unfolding atLeastLessThan_alt by auto |
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lemma |
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Rep_word_0:"0 <= Rep_word x" and |
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Rep_word_lt: "Rep_word (x::'a::len0 word) < 2 ^ len_of TYPE('a)" |
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by (auto simp: Rep_word [simplified]) |
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lemma Rep_word_mod_same: |
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"Rep_word x mod 2 ^ len_of TYPE('a) = Rep_word (x::'a::len0 word)" |
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by (simp add: int_mod_eq Rep_word_lt Rep_word_0) |
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lemma td_ext_uint: |
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"td_ext (uint :: 'a word => int) word_of_int (uints (len_of TYPE('a::len0))) |
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(%w::int. w mod 2 ^ len_of TYPE('a))" |
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apply (unfold td_ext_def') |
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apply (simp add: uints_num uint_def word_of_int_def bintrunc_mod2p) |
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apply (simp add: Rep_word_mod_same Rep_word_0 Rep_word_lt |
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word.Rep_word_inverse word.Abs_word_inverse int_mod_lem) |
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done |
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lemmas int_word_uint = td_ext_uint [THEN td_ext.eq_norm, standard] |
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interpretation word_uint: |
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td_ext ["uint::'a::len0 word \<Rightarrow> int" |
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word_of_int |
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"uints (len_of TYPE('a::len0))" |
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"\<lambda>w. w mod 2 ^ len_of TYPE('a::len0)"] |
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by (rule td_ext_uint) |
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lemmas td_uint = word_uint.td_thm |
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lemmas td_ext_ubin = td_ext_uint |
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[simplified len_gt_0 no_bintr_alt1 [symmetric]] |
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interpretation word_ubin: |
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td_ext ["uint::'a::len0 word \<Rightarrow> int" |
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word_of_int |
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"uints (len_of TYPE('a::len0))" |
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"bintrunc (len_of TYPE('a::len0))"] |
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by (rule td_ext_ubin) |
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lemma sint_sbintrunc': |
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"sint (word_of_int bin :: 'a word) = |
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(sbintrunc (len_of TYPE ('a :: len) - 1) bin)" |
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unfolding sint_uint |
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by (auto simp: word_ubin.eq_norm sbintrunc_bintrunc_lt) |
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lemma uint_sint: |
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"uint w = bintrunc (len_of TYPE('a)) (sint (w :: 'a :: len word))" |
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unfolding sint_uint by (auto simp: bintrunc_sbintrunc_le) |
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lemma bintr_uint': |
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"n >= size w ==> bintrunc n (uint w) = uint w" |
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apply (unfold word_size) |
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apply (subst word_ubin.norm_Rep [symmetric]) |
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apply (simp only: bintrunc_bintrunc_min word_size min_def) |
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apply simp |
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done |
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lemma wi_bintr': |
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"wb = word_of_int bin ==> n >= size wb ==> |
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word_of_int (bintrunc n bin) = wb" |
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unfolding word_size |
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by (clarsimp simp add : word_ubin.norm_eq_iff [symmetric] min_def) |
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lemmas bintr_uint = bintr_uint' [unfolded word_size] |
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lemmas wi_bintr = wi_bintr' [unfolded word_size] |
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lemma td_ext_sbin: |
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"td_ext (sint :: 'a word => int) word_of_int (sints (len_of TYPE('a::len))) |
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(sbintrunc (len_of TYPE('a) - 1))" |
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apply (unfold td_ext_def' sint_uint) |
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apply (simp add : word_ubin.eq_norm) |
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apply (cases "len_of TYPE('a)") |
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apply (auto simp add : sints_def) |
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apply (rule sym [THEN trans]) |
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apply (rule word_ubin.Abs_norm) |
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apply (simp only: bintrunc_sbintrunc) |
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apply (drule sym) |
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apply simp |
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done |
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lemmas td_ext_sint = td_ext_sbin |
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[simplified len_gt_0 no_sbintr_alt2 Suc_pred' [symmetric]] |
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(* We do sint before sbin, before sint is the user version |
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and interpretations do not produce thm duplicates. I.e. |
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we get the name word_sint.Rep_eqD, but not word_sbin.Req_eqD, |
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because the latter is the same thm as the former *) |
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interpretation word_sint: |
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td_ext ["sint ::'a::len word => int" |
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word_of_int |
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"sints (len_of TYPE('a::len))" |
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"%w. (w + 2^(len_of TYPE('a::len) - 1)) mod 2^len_of TYPE('a::len) - |
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2 ^ (len_of TYPE('a::len) - 1)"] |
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by (rule td_ext_sint) |
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interpretation word_sbin: |
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td_ext ["sint ::'a::len word => int" |
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word_of_int |
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"sints (len_of TYPE('a::len))" |
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"sbintrunc (len_of TYPE('a::len) - 1)"] |
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by (rule td_ext_sbin) |
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lemmas int_word_sint = td_ext_sint [THEN td_ext.eq_norm, standard] |
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lemmas td_sint = word_sint.td |
|
393 |
||
394 |
lemma word_number_of_alt: "number_of b == word_of_int (number_of b)" |
|
395 |
unfolding word_number_of_def by (simp add: number_of_eq) |
|
396 |
||
397 |
lemma word_no_wi: "number_of = word_of_int" |
|
398 |
by (auto simp: word_number_of_def intro: ext) |
|
399 |
||
24465 | 400 |
lemma to_bl_def': |
401 |
"(to_bl :: 'a :: len0 word => bool list) = |
|
402 |
bin_to_bl (len_of TYPE('a)) o uint" |
|
403 |
by (auto simp: to_bl_def intro: ext) |
|
404 |
||
25349
0d46bea01741
eliminated illegal schematic variables in where/of;
wenzelm
parents:
25149
diff
changeset
|
405 |
lemmas word_reverse_no_def [simp] = word_reverse_def [of "number_of w", standard] |
24465 | 406 |
|
24333 | 407 |
lemmas uints_mod = uints_def [unfolded no_bintr_alt1] |
408 |
||
409 |
lemma uint_bintrunc: "uint (number_of bin :: 'a word) = |
|
24465 | 410 |
number_of (bintrunc (len_of TYPE ('a :: len0)) bin)" |
24333 | 411 |
unfolding word_number_of_def number_of_eq |
412 |
by (auto intro: word_ubin.eq_norm) |
|
413 |
||
414 |
lemma sint_sbintrunc: "sint (number_of bin :: 'a word) = |
|
24465 | 415 |
number_of (sbintrunc (len_of TYPE ('a :: len) - 1) bin)" |
24333 | 416 |
unfolding word_number_of_def number_of_eq |
25149 | 417 |
by (subst word_sbin.eq_norm) simp |
24333 | 418 |
|
419 |
lemma unat_bintrunc: |
|
24465 | 420 |
"unat (number_of bin :: 'a :: len0 word) = |
421 |
number_of (bintrunc (len_of TYPE('a)) bin)" |
|
24333 | 422 |
unfolding unat_def nat_number_of_def |
423 |
by (simp only: uint_bintrunc) |
|
424 |
||
425 |
(* WARNING - these may not always be helpful *) |
|
426 |
declare |
|
427 |
uint_bintrunc [simp] |
|
428 |
sint_sbintrunc [simp] |
|
429 |
unat_bintrunc [simp] |
|
430 |
||
24465 | 431 |
lemma size_0_eq: "size (w :: 'a :: len0 word) = 0 ==> v = w" |
24333 | 432 |
apply (unfold word_size) |
433 |
apply (rule word_uint.Rep_eqD) |
|
434 |
apply (rule box_equals) |
|
435 |
defer |
|
436 |
apply (rule word_ubin.norm_Rep)+ |
|
437 |
apply simp |
|
438 |
done |
|
439 |
||
440 |
lemmas uint_lem = word_uint.Rep [unfolded uints_num mem_Collect_eq] |
|
441 |
lemmas sint_lem = word_sint.Rep [unfolded sints_num mem_Collect_eq] |
|
442 |
lemmas uint_ge_0 [iff] = uint_lem [THEN conjunct1, standard] |
|
443 |
lemmas uint_lt2p [iff] = uint_lem [THEN conjunct2, standard] |
|
444 |
lemmas sint_ge = sint_lem [THEN conjunct1, standard] |
|
445 |
lemmas sint_lt = sint_lem [THEN conjunct2, standard] |
|
446 |
||
447 |
lemma sign_uint_Pls [simp]: |
|
448 |
"bin_sign (uint x) = Numeral.Pls" |
|
449 |
by (simp add: sign_Pls_ge_0 number_of_eq) |
|
450 |
||
451 |
lemmas uint_m2p_neg = iffD2 [OF diff_less_0_iff_less uint_lt2p, standard] |
|
452 |
lemmas uint_m2p_not_non_neg = |
|
453 |
iffD2 [OF linorder_not_le uint_m2p_neg, standard] |
|
454 |
||
455 |
lemma lt2p_lem: |
|
24465 | 456 |
"len_of TYPE('a) <= n ==> uint (w :: 'a :: len0 word) < 2 ^ n" |
24333 | 457 |
by (rule xtr8 [OF _ uint_lt2p]) simp |
458 |
||
459 |
lemmas uint_le_0_iff [simp] = |
|
460 |
uint_ge_0 [THEN leD, THEN linorder_antisym_conv1, standard] |
|
461 |
||
462 |
lemma uint_nat: "uint w == int (unat w)" |
|
463 |
unfolding unat_def by auto |
|
464 |
||
465 |
lemma uint_number_of: |
|
24465 | 466 |
"uint (number_of b :: 'a :: len0 word) = number_of b mod 2 ^ len_of TYPE('a)" |
24333 | 467 |
unfolding word_number_of_alt |
468 |
by (simp only: int_word_uint) |
|
469 |
||
470 |
lemma unat_number_of: |
|
471 |
"bin_sign b = Numeral.Pls ==> |
|
24465 | 472 |
unat (number_of b::'a::len0 word) = number_of b mod 2 ^ len_of TYPE ('a)" |
24333 | 473 |
apply (unfold unat_def) |
474 |
apply (clarsimp simp only: uint_number_of) |
|
475 |
apply (rule nat_mod_distrib [THEN trans]) |
|
476 |
apply (erule sign_Pls_ge_0 [THEN iffD1]) |
|
477 |
apply (simp_all add: nat_power_eq) |
|
478 |
done |
|
479 |
||
24465 | 480 |
lemma sint_number_of: "sint (number_of b :: 'a :: len word) = (number_of b + |
481 |
2 ^ (len_of TYPE('a) - 1)) mod 2 ^ len_of TYPE('a) - |
|
482 |
2 ^ (len_of TYPE('a) - 1)" |
|
24333 | 483 |
unfolding word_number_of_alt by (rule int_word_sint) |
484 |
||
485 |
lemma word_of_int_bin [simp] : |
|
24465 | 486 |
"(word_of_int (number_of bin) :: 'a :: len0 word) = (number_of bin)" |
24333 | 487 |
unfolding word_number_of_alt by auto |
488 |
||
489 |
lemma word_int_case_wi: |
|
490 |
"word_int_case f (word_of_int i :: 'b word) = |
|
24465 | 491 |
f (i mod 2 ^ len_of TYPE('b::len0))" |
24333 | 492 |
unfolding word_int_case_def by (simp add: word_uint.eq_norm) |
493 |
||
494 |
lemma word_int_split: |
|
495 |
"P (word_int_case f x) = |
|
24465 | 496 |
(ALL i. x = (word_of_int i :: 'b :: len0 word) & |
497 |
0 <= i & i < 2 ^ len_of TYPE('b) --> P (f i))" |
|
24333 | 498 |
unfolding word_int_case_def |
499 |
by (auto simp: word_uint.eq_norm int_mod_eq') |
|
500 |
||
501 |
lemma word_int_split_asm: |
|
502 |
"P (word_int_case f x) = |
|
24465 | 503 |
(~ (EX n. x = (word_of_int n :: 'b::len0 word) & |
504 |
0 <= n & n < 2 ^ len_of TYPE('b::len0) & ~ P (f n)))" |
|
24333 | 505 |
unfolding word_int_case_def |
506 |
by (auto simp: word_uint.eq_norm int_mod_eq') |
|
507 |
||
508 |
lemmas uint_range' = |
|
509 |
word_uint.Rep [unfolded uints_num mem_Collect_eq, standard] |
|
510 |
lemmas sint_range' = word_sint.Rep [unfolded One_nat_def |
|
511 |
sints_num mem_Collect_eq, standard] |
|
512 |
||
513 |
lemma uint_range_size: "0 <= uint w & uint w < 2 ^ size w" |
|
514 |
unfolding word_size by (rule uint_range') |
|
515 |
||
516 |
lemma sint_range_size: |
|
517 |
"- (2 ^ (size w - Suc 0)) <= sint w & sint w < 2 ^ (size w - Suc 0)" |
|
518 |
unfolding word_size by (rule sint_range') |
|
519 |
||
520 |
lemmas sint_above_size = sint_range_size |
|
521 |
[THEN conjunct2, THEN [2] xtr8, folded One_nat_def, standard] |
|
522 |
||
523 |
lemmas sint_below_size = sint_range_size |
|
524 |
[THEN conjunct1, THEN [2] order_trans, folded One_nat_def, standard] |
|
525 |
||
24465 | 526 |
lemma test_bit_eq_iff: "(test_bit (u::'a::len0 word) = test_bit v) = (u = v)" |
24333 | 527 |
unfolding word_test_bit_def by (simp add: bin_nth_eq_iff) |
528 |
||
24465 | 529 |
lemma test_bit_size [rule_format] : "(w::'a::len0 word) !! n --> n < size w" |
24333 | 530 |
apply (unfold word_test_bit_def) |
531 |
apply (subst word_ubin.norm_Rep [symmetric]) |
|
532 |
apply (simp only: nth_bintr word_size) |
|
533 |
apply fast |
|
534 |
done |
|
535 |
||
536 |
lemma word_eqI [rule_format] : |
|
24465 | 537 |
fixes u :: "'a::len0 word" |
24333 | 538 |
shows "(ALL n. n < size u --> u !! n = v !! n) ==> u = v" |
539 |
apply (rule test_bit_eq_iff [THEN iffD1]) |
|
540 |
apply (rule ext) |
|
541 |
apply (erule allE) |
|
542 |
apply (erule impCE) |
|
543 |
prefer 2 |
|
544 |
apply assumption |
|
545 |
apply (auto dest!: test_bit_size simp add: word_size) |
|
546 |
done |
|
547 |
||
548 |
lemmas word_eqD = test_bit_eq_iff [THEN iffD2, THEN fun_cong, standard] |
|
549 |
||
550 |
lemma test_bit_bin': "w !! n = (n < size w & bin_nth (uint w) n)" |
|
551 |
unfolding word_test_bit_def word_size |
|
552 |
by (simp add: nth_bintr [symmetric]) |
|
553 |
||
554 |
lemmas test_bit_bin = test_bit_bin' [unfolded word_size] |
|
555 |
||
556 |
lemma bin_nth_uint_imp': "bin_nth (uint w) n --> n < size w" |
|
557 |
apply (unfold word_size) |
|
558 |
apply (rule impI) |
|
559 |
apply (rule nth_bintr [THEN iffD1, THEN conjunct1]) |
|
560 |
apply (subst word_ubin.norm_Rep) |
|
561 |
apply assumption |
|
562 |
done |
|
563 |
||
564 |
lemma bin_nth_sint': |
|
565 |
"n >= size w --> bin_nth (sint w) n = bin_nth (sint w) (size w - 1)" |
|
566 |
apply (rule impI) |
|
567 |
apply (subst word_sbin.norm_Rep [symmetric]) |
|
568 |
apply (simp add : nth_sbintr word_size) |
|
569 |
apply auto |
|
570 |
done |
|
571 |
||
572 |
lemmas bin_nth_uint_imp = bin_nth_uint_imp' [rule_format, unfolded word_size] |
|
573 |
lemmas bin_nth_sint = bin_nth_sint' [rule_format, unfolded word_size] |
|
574 |
||
24465 | 575 |
(* type definitions theorem for in terms of equivalent bool list *) |
576 |
lemma td_bl: |
|
577 |
"type_definition (to_bl :: 'a::len0 word => bool list) |
|
578 |
of_bl |
|
579 |
{bl. length bl = len_of TYPE('a)}" |
|
580 |
apply (unfold type_definition_def of_bl_def to_bl_def) |
|
581 |
apply (simp add: word_ubin.eq_norm) |
|
582 |
apply safe |
|
583 |
apply (drule sym) |
|
584 |
apply simp |
|
585 |
done |
|
586 |
||
587 |
interpretation word_bl: |
|
588 |
type_definition ["to_bl :: 'a::len0 word => bool list" |
|
589 |
of_bl |
|
590 |
"{bl. length bl = len_of TYPE('a::len0)}"] |
|
591 |
by (rule td_bl) |
|
592 |
||
593 |
lemma word_size_bl: "size w == size (to_bl w)" |
|
594 |
unfolding word_size by auto |
|
595 |
||
596 |
lemma to_bl_use_of_bl: |
|
597 |
"(to_bl w = bl) = (w = of_bl bl \<and> length bl = length (to_bl w))" |
|
598 |
by (fastsimp elim!: word_bl.Abs_inverse [simplified]) |
|
599 |
||
600 |
lemma to_bl_word_rev: "to_bl (word_reverse w) = rev (to_bl w)" |
|
601 |
unfolding word_reverse_def by (simp add: word_bl.Abs_inverse) |
|
602 |
||
603 |
lemma word_rev_rev [simp] : "word_reverse (word_reverse w) = w" |
|
604 |
unfolding word_reverse_def by (simp add : word_bl.Abs_inverse) |
|
605 |
||
606 |
lemma word_rev_gal: "word_reverse w = u ==> word_reverse u = w" |
|
607 |
by auto |
|
608 |
||
609 |
lemmas word_rev_gal' = sym [THEN word_rev_gal, symmetric, standard] |
|
610 |
||
611 |
lemmas length_bl_gt_0 [iff] = xtr1 [OF word_bl.Rep' len_gt_0, standard] |
|
612 |
lemmas bl_not_Nil [iff] = |
|
613 |
length_bl_gt_0 [THEN length_greater_0_conv [THEN iffD1], standard] |
|
614 |
lemmas length_bl_neq_0 [iff] = length_bl_gt_0 [THEN gr_implies_not0] |
|
615 |
||
616 |
lemma hd_bl_sign_sint: "hd (to_bl w) = (bin_sign (sint w) = Numeral.Min)" |
|
617 |
apply (unfold to_bl_def sint_uint) |
|
618 |
apply (rule trans [OF _ bl_sbin_sign]) |
|
619 |
apply simp |
|
620 |
done |
|
621 |
||
622 |
lemma of_bl_drop': |
|
623 |
"lend = length bl - len_of TYPE ('a :: len0) ==> |
|
624 |
of_bl (drop lend bl) = (of_bl bl :: 'a word)" |
|
625 |
apply (unfold of_bl_def) |
|
626 |
apply (clarsimp simp add : trunc_bl2bin [symmetric]) |
|
627 |
done |
|
628 |
||
629 |
lemmas of_bl_no = of_bl_def [folded word_number_of_def] |
|
630 |
||
631 |
lemma test_bit_of_bl: |
|
632 |
"(of_bl bl::'a::len0 word) !! n = (rev bl ! n \<and> n < len_of TYPE('a) \<and> n < length bl)" |
|
633 |
apply (unfold of_bl_def word_test_bit_def) |
|
634 |
apply (auto simp add: word_size word_ubin.eq_norm nth_bintr bin_nth_of_bl) |
|
635 |
done |
|
636 |
||
637 |
lemma no_of_bl: |
|
638 |
"(number_of bin ::'a::len0 word) = of_bl (bin_to_bl (len_of TYPE ('a)) bin)" |
|
639 |
unfolding word_size of_bl_no by (simp add : word_number_of_def) |
|
640 |
||
641 |
lemma uint_bl: "to_bl w == bin_to_bl (size w) (uint w)" |
|
642 |
unfolding word_size to_bl_def by auto |
|
643 |
||
644 |
lemma to_bl_bin: "bl_to_bin (to_bl w) = uint w" |
|
645 |
unfolding uint_bl by (simp add : word_size) |
|
646 |
||
647 |
lemma to_bl_of_bin: |
|
648 |
"to_bl (word_of_int bin::'a::len0 word) = bin_to_bl (len_of TYPE('a)) bin" |
|
649 |
unfolding uint_bl by (clarsimp simp add: word_ubin.eq_norm word_size) |
|
650 |
||
651 |
lemmas to_bl_no_bin [simp] = to_bl_of_bin [folded word_number_of_def] |
|
652 |
||
653 |
lemma to_bl_to_bin [simp] : "bl_to_bin (to_bl w) = uint w" |
|
654 |
unfolding uint_bl by (simp add : word_size) |
|
655 |
||
656 |
lemmas uint_bl_bin [simp] = trans [OF bin_bl_bin word_ubin.norm_Rep, standard] |
|
24333 | 657 |
|
658 |
lemmas num_AB_u [simp] = word_uint.Rep_inverse |
|
659 |
[unfolded o_def word_number_of_def [symmetric], standard] |
|
660 |
lemmas num_AB_s [simp] = word_sint.Rep_inverse |
|
661 |
[unfolded o_def word_number_of_def [symmetric], standard] |
|
662 |
||
663 |
(* naturals *) |
|
664 |
lemma uints_unats: "uints n = int ` unats n" |
|
665 |
apply (unfold unats_def uints_num) |
|
666 |
apply safe |
|
667 |
apply (rule_tac image_eqI) |
|
668 |
apply (erule_tac nat_0_le [symmetric]) |
|
669 |
apply auto |
|
670 |
apply (erule_tac nat_less_iff [THEN iffD2]) |
|
671 |
apply (rule_tac [2] zless_nat_eq_int_zless [THEN iffD1]) |
|
672 |
apply (auto simp add : nat_power_eq int_power) |
|
673 |
done |
|
674 |
||
675 |
lemma unats_uints: "unats n = nat ` uints n" |
|
25349
0d46bea01741
eliminated illegal schematic variables in where/of;
wenzelm
parents:
25149
diff
changeset
|
676 |
by (auto simp add : uints_unats image_iff) |
24333 | 677 |
|
678 |
lemmas bintr_num = word_ubin.norm_eq_iff |
|
679 |
[symmetric, folded word_number_of_def, standard] |
|
680 |
lemmas sbintr_num = word_sbin.norm_eq_iff |
|
681 |
[symmetric, folded word_number_of_def, standard] |
|
682 |
||
683 |
lemmas num_of_bintr = word_ubin.Abs_norm [folded word_number_of_def, standard] |
|
684 |
lemmas num_of_sbintr = word_sbin.Abs_norm [folded word_number_of_def, standard]; |
|
685 |
||
686 |
(* don't add these to simpset, since may want bintrunc n w to be simplified; |
|
687 |
may want these in reverse, but loop as simp rules, so use following *) |
|
688 |
||
689 |
lemma num_of_bintr': |
|
24465 | 690 |
"bintrunc (len_of TYPE('a :: len0)) a = b ==> |
24333 | 691 |
number_of a = (number_of b :: 'a word)" |
692 |
apply safe |
|
693 |
apply (rule_tac num_of_bintr [symmetric]) |
|
694 |
done |
|
695 |
||
696 |
lemma num_of_sbintr': |
|
24465 | 697 |
"sbintrunc (len_of TYPE('a :: len) - 1) a = b ==> |
24333 | 698 |
number_of a = (number_of b :: 'a word)" |
699 |
apply safe |
|
700 |
apply (rule_tac num_of_sbintr [symmetric]) |
|
701 |
done |
|
702 |
||
703 |
lemmas num_abs_bintr = sym [THEN trans, |
|
704 |
OF num_of_bintr word_number_of_def [THEN meta_eq_to_obj_eq], standard] |
|
705 |
lemmas num_abs_sbintr = sym [THEN trans, |
|
706 |
OF num_of_sbintr word_number_of_def [THEN meta_eq_to_obj_eq], standard] |
|
24465 | 707 |
|
24333 | 708 |
(** cast - note, no arg for new length, as it's determined by type of result, |
709 |
thus in "cast w = w, the type means cast to length of w! **) |
|
710 |
||
711 |
lemma ucast_id: "ucast w = w" |
|
712 |
unfolding ucast_def by auto |
|
713 |
||
714 |
lemma scast_id: "scast w = w" |
|
715 |
unfolding scast_def by auto |
|
716 |
||
24465 | 717 |
lemma ucast_bl: "ucast w == of_bl (to_bl w)" |
718 |
unfolding ucast_def of_bl_def uint_bl |
|
719 |
by (auto simp add : word_size) |
|
720 |
||
24333 | 721 |
lemma nth_ucast: |
24465 | 722 |
"(ucast w::'a::len0 word) !! n = (w !! n & n < len_of TYPE('a))" |
24333 | 723 |
apply (unfold ucast_def test_bit_bin) |
724 |
apply (simp add: word_ubin.eq_norm nth_bintr word_size) |
|
725 |
apply (fast elim!: bin_nth_uint_imp) |
|
726 |
done |
|
727 |
||
728 |
(* for literal u(s)cast *) |
|
729 |
||
730 |
lemma ucast_bintr [simp]: |
|
24465 | 731 |
"ucast (number_of w ::'a::len0 word) = |
732 |
number_of (bintrunc (len_of TYPE('a)) w)" |
|
24333 | 733 |
unfolding ucast_def by simp |
734 |
||
735 |
lemma scast_sbintr [simp]: |
|
24465 | 736 |
"scast (number_of w ::'a::len word) = |
737 |
number_of (sbintrunc (len_of TYPE('a) - Suc 0) w)" |
|
24333 | 738 |
unfolding scast_def by simp |
739 |
||
740 |
lemmas source_size = source_size_def [unfolded Let_def word_size] |
|
741 |
lemmas target_size = target_size_def [unfolded Let_def word_size] |
|
742 |
lemmas is_down = is_down_def [unfolded source_size target_size] |
|
743 |
lemmas is_up = is_up_def [unfolded source_size target_size] |
|
744 |
||
745 |
lemmas is_up_down = |
|
746 |
trans [OF is_up [THEN meta_eq_to_obj_eq] |
|
747 |
is_down [THEN meta_eq_to_obj_eq, symmetric], |
|
748 |
standard] |
|
749 |
||
750 |
lemma down_cast_same': "uc = ucast ==> is_down uc ==> uc = scast" |
|
751 |
apply (unfold is_down) |
|
752 |
apply safe |
|
753 |
apply (rule ext) |
|
754 |
apply (unfold ucast_def scast_def uint_sint) |
|
755 |
apply (rule word_ubin.norm_eq_iff [THEN iffD1]) |
|
756 |
apply simp |
|
757 |
done |
|
758 |
||
24465 | 759 |
lemma word_rev_tf': |
760 |
"r = to_bl (of_bl bl) ==> r = rev (takefill False (length r) (rev bl))" |
|
761 |
unfolding of_bl_def uint_bl |
|
762 |
by (clarsimp simp add: bl_bin_bl_rtf word_ubin.eq_norm word_size) |
|
763 |
||
764 |
lemmas word_rev_tf = refl [THEN word_rev_tf', unfolded word_bl.Rep', standard] |
|
765 |
||
766 |
lemmas word_rep_drop = word_rev_tf [simplified takefill_alt, |
|
767 |
simplified, simplified rev_take, simplified] |
|
768 |
||
769 |
lemma to_bl_ucast: |
|
770 |
"to_bl (ucast (w::'b::len0 word) ::'a::len0 word) = |
|
771 |
replicate (len_of TYPE('a) - len_of TYPE('b)) False @ |
|
772 |
drop (len_of TYPE('b) - len_of TYPE('a)) (to_bl w)" |
|
773 |
apply (unfold ucast_bl) |
|
774 |
apply (rule trans) |
|
775 |
apply (rule word_rep_drop) |
|
776 |
apply simp |
|
777 |
done |
|
778 |
||
779 |
lemma ucast_up_app': |
|
780 |
"uc = ucast ==> source_size uc + n = target_size uc ==> |
|
781 |
to_bl (uc w) = replicate n False @ (to_bl w)" |
|
782 |
apply (auto simp add : source_size target_size to_bl_ucast) |
|
783 |
apply (rule_tac f = "%n. replicate n False" in arg_cong) |
|
784 |
apply simp |
|
785 |
done |
|
786 |
||
787 |
lemma ucast_down_drop': |
|
788 |
"uc = ucast ==> source_size uc = target_size uc + n ==> |
|
789 |
to_bl (uc w) = drop n (to_bl w)" |
|
790 |
by (auto simp add : source_size target_size to_bl_ucast) |
|
791 |
||
792 |
lemma scast_down_drop': |
|
793 |
"sc = scast ==> source_size sc = target_size sc + n ==> |
|
794 |
to_bl (sc w) = drop n (to_bl w)" |
|
795 |
apply (subgoal_tac "sc = ucast") |
|
796 |
apply safe |
|
797 |
apply simp |
|
798 |
apply (erule refl [THEN ucast_down_drop']) |
|
799 |
apply (rule refl [THEN down_cast_same', symmetric]) |
|
800 |
apply (simp add : source_size target_size is_down) |
|
801 |
done |
|
802 |
||
24333 | 803 |
lemma sint_up_scast': |
804 |
"sc = scast ==> is_up sc ==> sint (sc w) = sint w" |
|
805 |
apply (unfold is_up) |
|
806 |
apply safe |
|
807 |
apply (simp add: scast_def word_sbin.eq_norm) |
|
808 |
apply (rule box_equals) |
|
809 |
prefer 3 |
|
810 |
apply (rule word_sbin.norm_Rep) |
|
811 |
apply (rule sbintrunc_sbintrunc_l) |
|
812 |
defer |
|
813 |
apply (subst word_sbin.norm_Rep) |
|
814 |
apply (rule refl) |
|
815 |
apply simp |
|
816 |
done |
|
817 |
||
818 |
lemma uint_up_ucast': |
|
819 |
"uc = ucast ==> is_up uc ==> uint (uc w) = uint w" |
|
820 |
apply (unfold is_up) |
|
821 |
apply safe |
|
822 |
apply (rule bin_eqI) |
|
823 |
apply (fold word_test_bit_def) |
|
824 |
apply (auto simp add: nth_ucast) |
|
825 |
apply (auto simp add: test_bit_bin) |
|
826 |
done |
|
827 |
||
828 |
lemmas down_cast_same = refl [THEN down_cast_same'] |
|
24465 | 829 |
lemmas ucast_up_app = refl [THEN ucast_up_app'] |
830 |
lemmas ucast_down_drop = refl [THEN ucast_down_drop'] |
|
831 |
lemmas scast_down_drop = refl [THEN scast_down_drop'] |
|
24333 | 832 |
lemmas uint_up_ucast = refl [THEN uint_up_ucast'] |
833 |
lemmas sint_up_scast = refl [THEN sint_up_scast'] |
|
834 |
||
835 |
lemma ucast_up_ucast': "uc = ucast ==> is_up uc ==> ucast (uc w) = ucast w" |
|
836 |
apply (simp (no_asm) add: ucast_def) |
|
837 |
apply (clarsimp simp add: uint_up_ucast) |
|
838 |
done |
|
839 |
||
840 |
lemma scast_up_scast': "sc = scast ==> is_up sc ==> scast (sc w) = scast w" |
|
841 |
apply (simp (no_asm) add: scast_def) |
|
842 |
apply (clarsimp simp add: sint_up_scast) |
|
843 |
done |
|
844 |
||
24465 | 845 |
lemma ucast_of_bl_up': |
846 |
"w = of_bl bl ==> size bl <= size w ==> ucast w = of_bl bl" |
|
847 |
by (auto simp add : nth_ucast word_size test_bit_of_bl intro!: word_eqI) |
|
848 |
||
24333 | 849 |
lemmas ucast_up_ucast = refl [THEN ucast_up_ucast'] |
850 |
lemmas scast_up_scast = refl [THEN scast_up_scast'] |
|
24465 | 851 |
lemmas ucast_of_bl_up = refl [THEN ucast_of_bl_up'] |
24333 | 852 |
|
853 |
lemmas ucast_up_ucast_id = trans [OF ucast_up_ucast ucast_id] |
|
854 |
lemmas scast_up_scast_id = trans [OF scast_up_scast scast_id] |
|
855 |
||
856 |
lemmas isduu = is_up_down [where c = "ucast", THEN iffD2] |
|
857 |
lemmas isdus = is_up_down [where c = "scast", THEN iffD2] |
|
858 |
lemmas ucast_down_ucast_id = isduu [THEN ucast_up_ucast_id] |
|
859 |
lemmas scast_down_scast_id = isdus [THEN ucast_up_ucast_id] |
|
860 |
||
861 |
lemma up_ucast_surj: |
|
24465 | 862 |
"is_up (ucast :: 'b::len0 word => 'a::len0 word) ==> |
24333 | 863 |
surj (ucast :: 'a word => 'b word)" |
864 |
by (rule surjI, erule ucast_up_ucast_id) |
|
865 |
||
866 |
lemma up_scast_surj: |
|
24465 | 867 |
"is_up (scast :: 'b::len word => 'a::len word) ==> |
24333 | 868 |
surj (scast :: 'a word => 'b word)" |
869 |
by (rule surjI, erule scast_up_scast_id) |
|
870 |
||
871 |
lemma down_scast_inj: |
|
24465 | 872 |
"is_down (scast :: 'b::len word => 'a::len word) ==> |
24333 | 873 |
inj_on (ucast :: 'a word => 'b word) A" |
874 |
by (rule inj_on_inverseI, erule scast_down_scast_id) |
|
875 |
||
876 |
lemma down_ucast_inj: |
|
24465 | 877 |
"is_down (ucast :: 'b::len0 word => 'a::len0 word) ==> |
24333 | 878 |
inj_on (ucast :: 'a word => 'b word) A" |
879 |
by (rule inj_on_inverseI, erule ucast_down_ucast_id) |
|
880 |
||
24465 | 881 |
lemma of_bl_append_same: "of_bl (X @ to_bl w) = w" |
882 |
by (rule word_bl.Rep_eqD) (simp add: word_rep_drop) |
|
24333 | 883 |
|
884 |
lemma ucast_down_no': |
|
885 |
"uc = ucast ==> is_down uc ==> uc (number_of bin) = number_of bin" |
|
886 |
apply (unfold word_number_of_def is_down) |
|
887 |
apply (clarsimp simp add: ucast_def word_ubin.eq_norm) |
|
888 |
apply (rule word_ubin.norm_eq_iff [THEN iffD1]) |
|
889 |
apply (erule bintrunc_bintrunc_ge) |
|
890 |
done |
|
891 |
||
892 |
lemmas ucast_down_no = ucast_down_no' [OF refl] |
|
893 |
||
24465 | 894 |
lemma ucast_down_bl': "uc = ucast ==> is_down uc ==> uc (of_bl bl) = of_bl bl" |
895 |
unfolding of_bl_no by clarify (erule ucast_down_no) |
|
896 |
||
897 |
lemmas ucast_down_bl = ucast_down_bl' [OF refl] |
|
898 |
||
899 |
lemmas slice_def' = slice_def [unfolded word_size] |
|
900 |
lemmas test_bit_def' = word_test_bit_def [THEN meta_eq_to_obj_eq, THEN fun_cong] |
|
901 |
||
902 |
lemmas word_log_defs = word_and_def word_or_def word_xor_def word_not_def |
|
903 |
lemmas word_log_bin_defs = word_log_defs |
|
904 |
||
24333 | 905 |
end |