# Changelog for the [`ghc-typelits-natnormalise`](http://hackage.haskell.org/package/ghc-typelits-natnormalise) package ## 0.5.6 *October 31st 2017* * Fixes bugs: * `(x + 1) ~ (2 * y)` no longer implies `((2 * (y - 1)) + 1) ~ x` ## 0.5.5 *October 22nd 2017* * Solve inequalities when their normal forms are the same, i.e. * `(2 <= (2 ^ (n + d)))` implies `(2 <= (2 ^ (d + n)))` * Find more unifications: * `8^x - 2*4^x ~ 8^y - 2*4^y ==> [x := y]` ## 0.5.4 *October 14th 2017* * Perform normalisations such as: `2^x * 4^x ==> 8^x` ## 0.5.3 *May 15th 2017* * Add support for GHC 8.2 ## 0.5.2 *January 15th 2017* * Fixes bugs: * Reification from SOP to Type sometimes loses product terms ## 0.5.1 *September 29th 2016* * Fixes bugs: * Cannot solve an equality for the second time in a definition group ## 0.5 *August 17th 2016* * Solve simple inequalities, i.e.: * `a <= a + 1` * `2a <= 3a` * `1 <= a^b` ## 0.4.6 *July 21th 2016* * Reduce "x^(-y) * x^y" to 1 * Fixes bugs: * Subtraction in exponent induces infinite loop ## 0.4.5 *July 20th 2016* * Fixes bugs: * Reifying negative exponent causes GHC panic ## 0.4.4 *July 19th 2016* * Fixes bugs: * Rounding error in `logBase` calculation ## 0.4.3 *July 18th 2016* * Fixes bugs: * False positive: "f :: (CLog 2 (2 ^ n) ~ n, (1 <=? n) ~ True) => Proxy n -> Proxy (n+d)" ## 0.4.2 *July 8th 2016* * Find more unifications: * `(2*e ^ d) ~ (2*e*a*c) ==> [a*c := 2*e ^ (d-1)]` * `a^d * a^e ~ a^c ==> [c := d + e]` * `x+5 ~ y ==> [x := y - 5]`, but only when `x+5 ~ y` is a given constraint ## 0.4.1 *February 4th 2016* * Find more unifications: * `F x y k z ~ F x y (k-1+1) z` ==> [k := k], where `F` can be any type function ## 0.4 *January 19th 2016* * Stop using 'provenance' hack to create conditional evidence (GHC 8.0+ only) * Find more unifications: * `F x + 2 - 1 - 1 ~ F x` ==> [F x := F x], where `F` can be any type function with result `Nat`. ## 0.3.2 * Find more unifications: * `(z ^ a) ~ (z ^ b) ==> [a := b]` * `(i ^ a) ~ j ==> [a := round (logBase i j)]`, when `i` and `j` are integers, and `ceiling (logBase i j) == floor (logBase i j)`. ## 0.3.1 *October 19th 2015* * Find more unifications: * `(i * a) ~ j ==> [a := div j i]`, when `i` and `j` are integers, and `mod j i == 0`. * `(i * a) + j ~ k ==> [a := div (k-j) i]`, when `i`, `j`, and `k` are integers, and `k-j >= 0` and `mod (k-j) i == 0`. ## 0.3 *June 3rd 2015* * Find more unifications: * ` + x ~ 2 + x ==> [ ~ 2]` * Fixes bugs: * Unifying `a*b ~ b` now returns `[a ~ 1]`; before it erroneously returned `[a ~ ]`, which is interpred as `[a ~ 0]`... * Unifying `a+b ~ b` now returns `[a ~ 0]`; before it returned the undesirable, though equal, `[a ~ ]` ## 0.2.1 *May 6th 2015* * Update `Eq` instance of `SOP`: Empty SOP is equal to 0 ## 0.2 *April 22nd 2015* * Finds more unifications: * `(2 + a) ~ 5 ==> [a := 3]` * `(3 * a) ~ 0 ==> [a := 0]` ## 0.1.2 *April 21st 2015* * Don't simplify expressions with negative exponents ## 0.1.1 *April 17th 2015* * Add workaround for https://ghc.haskell.org/trac/ghc/ticket/10301 ## 0.1 *March 30th 2015* * Initial release