feat: theorems for ushiftRight
#33
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@mhk119 I just pushed to the PR, and broke the proof strategy down into smaller chunks so it's easier to upstream. Let me know what you think, and if you're happy with the PR. |
This looks good ! |
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| theorem shiftRight_zero (n : Int) : n >>> 0 = n := by | ||
| simp [Int.shiftRight_eq_div_pow] |
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| /-- | ||
| Unsigned shift right by at least one bit makes the value of the bitvector less than or equal to `2^(w-1)`, | ||
| makes the interpretation of the bitvector `Int` and `Nat` agree. |
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makes the two times in a row is grammatically suspicious.
| have := show 2 * x.toNat >>> n < 2 ^ w by | ||
| omega | ||
| omega | ||
| · have : x.toNat >>> n = 0 := by |
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Can this be simplified with ushiftRight_eq_zero?
Co-authored-by: Tobias Grosser <[email protected]>
Co-authored-by: Tobias Grosser <[email protected]>
Co-authored-by: Tobias Grosser <[email protected]>
Co-authored-by: Tobias Grosser <[email protected]>
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