wordsLib.WORD_BIT_EQ

STRUCTURE

SYNOPSIS

Simplification fragment for words.

DESCRIPTION

The fragment WORD_BIT_EQ_ss simplifies using fcpLib.FCP_ss and the definitions of "bitwise" operations, e.g., conjunction, disjunction, 1’s complement, shifts, concatenation and sub-word extraction. Can be used in combination with decision procedures to test for the bitwise equality of words.

EXAMPLE

- SIMP_CONV (std_ss++WORD_BIT_EQ_ss) [] ``a = b : 'a word``
> val it = |- (a = b) = !i. i < dimindex (:'a) ==> (a ' i = b ' i) : thm

Further simplification occurs when the word length is known.

- SIMP_CONV (std_ss++WORD_BIT_EQ_ss) [] ``a = b : word2``
> val it = |- (a = b) = (a ' 1 = b ' 1) /\ (a ' 0 = b ' 0) : thm

Best used in combination with decision procedures.

- (SIMP_CONV (std_ss++WORD_BIT_EQ_ss) [] THENC tautLib.TAUT_CONV) ``a && b && a = a && b``
<<HOL message: inventing new type variable names: 'a>>
> val it = |- (a && b && a = a && b) = T : thm

COMMENTS

This fragment is not included in WORDS_ss.

SEEALSO

WORD_BIT_EQ_CONV, FCP_ss, BBLAST_CONV, BIT_ss, SIZES_ss, WORD_ARITH_ss, WORD_LOGIC_ss, WORD_SHIFT_ss, WORD_ARITH_EQ_ss, WORD_EXTRACT_ss, WORD_MUL_LSL_ss, WORD_ss