diff --git a/packages/squiggle-lang/__tests__/ReducerInterface/ReducerInterface_Distribution_test.res b/packages/squiggle-lang/__tests__/ReducerInterface/ReducerInterface_Distribution_test.res
index b514232a..85d80919 100644
--- a/packages/squiggle-lang/__tests__/ReducerInterface/ReducerInterface_Distribution_test.res
+++ b/packages/squiggle-lang/__tests__/ReducerInterface/ReducerInterface_Distribution_test.res
@@ -11,25 +11,43 @@ let testEval = (~skip=false, str, result) =>
 let testParse = (~skip=false, str, result) =>
   testSkip(skip)(str, () => Reducer_TestHelpers.expectParseToBe(str, result))
 
-describe("eval", () => {
-  describe("expressions", () => {
+describe("eval on distribution functions", () => {
+  describe("normal distribution", () => {
     testEval("normal(5,2)", "Ok(Normal(5,2))")
+  })
+  describe("lognormal distribution", () => {
+    testEval("lognormal(5,2)", "Ok(Lognormal(5,2))")
+  })
+  describe("unaryMinus", () => {
+    testEval("mean(-normal(5,2))", "Ok(-5.002887370380851)")
+  })
+  describe("to", () => {
     testEval("5 to 2", "Error(TODO: Low value must be less than high value.)")
     testEval("to(2,5)", "Ok(Lognormal(1.1512925464970227,0.278507821238345))")
     testEval("to(-2,2)", "Ok(Normal(0,1.215913388057542))")
-    testEval("lognormal(5,2)", "Ok(Lognormal(5,2))")
+  })
+  describe("mean", () => {
     testEval("mean(normal(5,2))", "Ok(5)")
     testEval("mean(lognormal(1,2))", "Ok(20.085536923187668)")
+  })
+  describe("normalize", () => {
     testEval("normalize(normal(5,2))", "Ok(Normal(5,2))")
+  })
+  describe("toPointSet", () => {
     testEval("toPointSet(normal(5,2))", "Ok(Point Set Distribution)")
+  })
+  describe("toSampleSet", () => {
     testEval("toSampleSet(normal(5,2), 100)", "Ok(Sample Set Distribution)")
+  })
+  describe("add", () => {
     testEval("add(normal(5,2), normal(10,2))", "Ok(Normal(15,2.8284271247461903))")
     testEval("add(normal(5,2), lognormal(10,2))", "Ok(Sample Set Distribution)")
     testEval("add(normal(5,2), 3)", "Ok(Point Set Distribution)")
     testEval("add(3, normal(5,2))", "Ok(Point Set Distribution)")
     testEval("3+normal(5,2)", "Ok(Point Set Distribution)")
     testEval("normal(5,2)+3", "Ok(Point Set Distribution)")
-    testEval("add(3, 3)", "Ok(6)")
+  })
+  describe("truncate", () => {
     testEval("truncateLeft(normal(5,2), 3)", "Ok(Point Set Distribution)")
     testEval("truncateRight(normal(5,2), 3)", "Ok(Point Set Distribution)")
     testEval("truncate(normal(5,2), 3, 8)", "Ok(Point Set Distribution)")
@@ -82,25 +100,26 @@ describe("eval", () => {
   })
 })
 
-describe("MathJs parse", () => {
-  describe("literals operators paranthesis", () => {
-    testParse("mean(normal(5,2) + normal(5,1))", "Ok((:mean (:add (:normal 5 2) (:normal 5 1))))")
-    testParse("normal(5,2) .* normal(5,1)", "Ok((:dotMultiply (:normal 5 2) (:normal 5 1)))")
-    testParse("normal(5,2) ./ normal(5,1)", "Ok((:dotDivide (:normal 5 2) (:normal 5 1)))")
-    testParse("normal(5,2) .^ normal(5,1)", "Ok((:dotPow (:normal 5 2) (:normal 5 1)))")
+describe("parse on distribution functions", () => {
+  describe("power", () => {
     testParse("normal(5,2) ^ normal(5,1)", "Ok((:pow (:normal 5 2) (:normal 5 1)))")
     testParse("3 ^ normal(5,1)", "Ok((:pow 3 (:normal 5 1)))")
     testParse("normal(5,2) ^ 3", "Ok((:pow (:normal 5 2) 3))")
+  })
+  describe("pointwise arithmetic expressions", () => {
+    testParse(~skip=true, "normal(5,2) .+ normal(5,1)", "Ok((:dotAdd (:normal 5 2) (:normal 5 1)))")
+    testParse(~skip=true, "normal(5,2) .- normal(5,1)", "Ok((:dotSubtract (:normal 5 2) (:normal 5 1)))")
+    testParse("normal(5,2) .* normal(5,1)", "Ok((:dotMultiply (:normal 5 2) (:normal 5 1)))")
+    testParse("normal(5,2) ./ normal(5,1)", "Ok((:dotDivide (:normal 5 2) (:normal 5 1)))")
+    testParse("normal(5,2) .^ normal(5,1)", "Ok((:dotPow (:normal 5 2) (:normal 5 1)))")
+  })
+  describe("equality", () => {
     testParse("5 == normal(5,2)", "Ok((:equal 5 (:normal 5 2)))")
-    describe("adding two normals", () => {
-      testParse(
-        ~skip=true,
-        "normal(5,2) .+ normal(5,1)",
-        "Ok((:dotAdd (:normal 5 2) (:normal 5 1)))",
-      )
-    })
-    describe("exponential of one distribution", () => {
-      testParse(~skip=true, "exp(normal(5,2)", "Ok((:pow (:normal 5 2) 3))")
-    })
+  })
+  describe("pointwise adding two normals", () => {
+    testParse(~skip=true, "normal(5,2) .+ normal(5,1)", "Ok((:dotAdd (:normal 5 2) (:normal 5 1)))")
+  })
+  describe("exponential of one distribution", () => {
+    testParse(~skip=true, "exp(normal(5,2)", "Ok((:pow (:normal 5 2) 3))")
   })
 })
diff --git a/packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_GenericDistribution.res b/packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_GenericDistribution.res
index 11376001..8fabdfa8 100644
--- a/packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_GenericDistribution.res
+++ b/packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_GenericDistribution.res
@@ -139,6 +139,8 @@ let dispatchToGenericOutput = (call: ExpressionValue.functionCall): option<
     Helpers.twoDiststoDistFn(Algebraic, "log", a, GenericDist.fromFloat(Math.e))->Some
   | ("log10", [EvDistribution(a)]) =>
     Helpers.twoDiststoDistFn(Algebraic, "log", a, GenericDist.fromFloat(10.0))->Some
+  | ("unaryMinus", [EvDistribution(a)]) =>
+    Helpers.twoDiststoDistFn(Algebraic, "multiply", a, GenericDist.fromFloat(-1.0))->Some
   | (("add" | "multiply" | "subtract" | "divide" | "pow" | "log") as arithmetic, [a, b] as args) =>
     Helpers.catchAndConvertTwoArgsToDists(args)->E.O2.fmap(((fst, snd)) =>
       Helpers.twoDiststoDistFn(Algebraic, arithmetic, fst, snd)