diff --git a/build.sbt b/build.sbt
index aec77c1..154197f 100644
--- a/build.sbt
+++ b/build.sbt
@@ -36,8 +36,6 @@ lazy val core = crossProject(
   NativePlatform
 ).crossType(CrossType.Full)
   .settings(
-    description := "Dyanmic extensions for slash",
-    libraryDependencies ++= Seq("ai.dragonfly" %%% "slash" % "0.1")
   )
   .jvmSettings(
   )
diff --git a/core/shared/src/main/scala/vecxt/array.extensions.scala b/core/shared/src/main/scala/vecxt/array.extensions.scala
index 3143a8d..3ec8492 100644
--- a/core/shared/src/main/scala/vecxt/array.extensions.scala
+++ b/core/shared/src/main/scala/vecxt/array.extensions.scala
@@ -14,11 +14,13 @@
  * limitations under the License.
  */
 
-package vexct
-import vexct.Limits.Limit
-import vexct.Retentions.Retention
+package vecxt
+import vecxt.Limits.Limit
+import vecxt.Retentions.Retention
 
 import scala.util.chaining.*
+import vecxt.BoundsCheck
+
 
 enum LossCalc:
   case Agg, Occ
@@ -56,7 +58,7 @@ end extension
 
 extension (vec: Array[Double])
 
-  def idx(index: Array[Boolean]) =
+  def idxBoolean(index: Array[Boolean]) =
     val trues = index.countTrue
     val newVec = new Array[Double](trues)
     var j = 0
@@ -67,7 +69,7 @@ extension (vec: Array[Double])
         j += 1
     end for
     newVec
-  end idx
+  end idxBoolean
 
   def increments: Array[Double] =
     val out = new Array[Double](vec.length)
@@ -99,7 +101,7 @@ extension (vec: Array[Double])
     sum
   end sum
 
-  def cumsum =
+  inline def cumsum =
     var i = 1
     while i < vec.length do
       vec(i) = vec(i - 1) + vec(i)
@@ -107,7 +109,8 @@ extension (vec: Array[Double])
     end while
   end cumsum
 
-  def -(vec2: Array[Double]) =
+  inline def -(vec2: Array[Double])(using inline boundsCheck : BoundsCheck) =
+    dimCheck(vec, vec2)
     val out = new Array[Double](vec.length)
     var i = 0
     while i < vec.length do
@@ -117,7 +120,7 @@ extension (vec: Array[Double])
     out
   end -
 
-  def -=(vec2: Array[Double]): Unit =
+  inline def -=(vec2: Array[Double]): Unit =
     var i = 0
     while i < vec.length do
       vec(i) = vec(i) - vec2(i)
@@ -125,7 +128,7 @@ extension (vec: Array[Double])
     end while
   end -=
 
-  def +(vec2: Array[Double]) =
+  inline def +(vec2: Array[Double]) =
     val out = new Array[Double](vec.length)
     var i = 0
     while i < vec.length do
@@ -135,7 +138,7 @@ extension (vec: Array[Double])
     out
   end +
 
-  def +=(vec2: Array[Double]): Unit =
+  inline def +=(vec2: Array[Double]): Unit =
     var i = 0
     while i < vec.length do
       vec(i) = vec(i) + vec2(i)
@@ -143,7 +146,7 @@ extension (vec: Array[Double])
     end while
   end +=
 
-  def *=(d: Double) =
+  inline def *=(d: Double) =
     var i = 0
     while i < vec.length do
       vec(i) = vec(i) * d
@@ -152,7 +155,7 @@ extension (vec: Array[Double])
     vec
   end *=
 
-  def *(d: Double) =
+  inline def *(d: Double) =
     val out = new Array[Double](vec.length)
     var i = 0
     while i < vec.length do
diff --git a/core/shared/src/main/scala/vecxt/bounds.check.scala b/core/shared/src/main/scala/vecxt/bounds.check.scala
new file mode 100644
index 0000000..d0b67dd
--- /dev/null
+++ b/core/shared/src/main/scala/vecxt/bounds.check.scala
@@ -0,0 +1,16 @@
+package vecxt
+
+// opaque type BoundsCheck = Boolean
+
+// object BoundsCheck:
+//   inline def apply(inline d: Boolean): BoundsCheck = d
+// end BoundsCheck
+
+// extension (inline bc: BoundsCheck) inline def value: Boolean = bc.self
+
+type BoundsCheck = Boolean
+
+object BoundsCheck:
+  inline given yes : BoundsCheck = true
+  inline given no : BoundsCheck = false
+end BoundsCheck
diff --git a/core/shared/src/main/scala/vecxt/dimCheck.scala b/core/shared/src/main/scala/vecxt/dimCheck.scala
index d883bc9..8319660 100644
--- a/core/shared/src/main/scala/vecxt/dimCheck.scala
+++ b/core/shared/src/main/scala/vecxt/dimCheck.scala
@@ -17,9 +17,10 @@
 package vecxt
 
 object dimCheck:
-  inline def apply[A, B](a: Array[A], b : Array[B]) =
-      if a.length != b.length then throw UnsupportedVectorDimension(a.length, b.length)
+  inline def apply[A, B](a: Array[A], b : Array[B]) (using inline doCheck: BoundsCheck)=
+      inline if doCheck then
+        if a.length != b.length then throw VectorDimensionMismatch(a.length, b.length)
 
-case class UnsupportedVectorDimension(givenDimension:Int, requiredDimension:Int) extends Exception(
+case class VectorDimensionMismatch(givenDimension:Int, requiredDimension:Int) extends Exception(
   s"Expected Vector dimensions to match. First dimension was : $requiredDimension, second was : $givenDimension ."
 )
diff --git a/core/shared/src/main/scala/vecxt/limit.rpt.scala b/core/shared/src/main/scala/vecxt/limit.rpt.scala
index e204a8d..3566244 100644
--- a/core/shared/src/main/scala/vecxt/limit.rpt.scala
+++ b/core/shared/src/main/scala/vecxt/limit.rpt.scala
@@ -14,9 +14,9 @@
  * limitations under the License.
  */
 
-package vexct
+package vecxt
 
-import vexct.Retentions.*
+import vecxt.Retentions.*
 
 object Limits:
   opaque type Limit = Double
diff --git a/core/shared/src/main/scala/vecxt/main.scala b/core/shared/src/main/scala/vecxt/main.scala
new file mode 100644
index 0000000..48c03e8
--- /dev/null
+++ b/core/shared/src/main/scala/vecxt/main.scala
@@ -0,0 +1,11 @@
+package vecxt
+
+
+@main def checkBytecode =
+  val a = Array[Double](1,2,3)
+  val a1 = Array[Double](1,2,3)
+  // val b = Array[Boolean](true, false, true)
+  // val c = Array[Boolean](false, true, true)
+
+  import vecxt.BoundsCheck.yes
+  a - a1
\ No newline at end of file
diff --git a/core/shared/src/main/scala/vecxt/retention.rpt.scala b/core/shared/src/main/scala/vecxt/retention.rpt.scala
index 53d68fd..fc64317 100644
--- a/core/shared/src/main/scala/vecxt/retention.rpt.scala
+++ b/core/shared/src/main/scala/vecxt/retention.rpt.scala
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package vexct
+package vecxt
 
 object Retentions:
   opaque type Retention = Double
diff --git a/tests/shared/src/test/scala/arrayExtensions.test.scala b/tests/shared/src/test/scala/arrayExtensions.test.scala
index 7d58b37..b1fa5d1 100644
--- a/tests/shared/src/test/scala/arrayExtensions.test.scala
+++ b/tests/shared/src/test/scala/arrayExtensions.test.scala
@@ -14,11 +14,12 @@
  * limitations under the License.
  */
 
-package vexct
+package vecxt
 
 import scala.util.chaining.*
 
 class ArrayExtensionSuite extends munit.FunSuite:
+  import vecxt.BoundsCheck.yes
 
   lazy val v_fill = Array.tabulate(5)(i => i.toDouble)
 
@@ -142,7 +143,7 @@ class ArrayExtensionSuite extends munit.FunSuite:
   test("Array indexing") {
     val v1 = Array[Double](1.0, 2.0, 3.0)
     val vIdx = Array[Boolean](true, false, true)
-    val afterIndex = v1.idx(vIdx)
+    val afterIndex = v1.idxBoolean(vIdx)
 
     assertEquals(afterIndex.length, 2)
     assertEqualsDouble(afterIndex.head, 1, 0.0001)
diff --git a/tests/shared/src/test/scala/boundsCheck.scala b/tests/shared/src/test/scala/boundsCheck.scala
new file mode 100644
index 0000000..1d43118
--- /dev/null
+++ b/tests/shared/src/test/scala/boundsCheck.scala
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2023 quafadas
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package vecxt
+
+import scala.util.chaining.*
+
+class BoundsCheckSuite extends munit.FunSuite:
+
+
+  lazy val v_fill = Array.tabulate(5)(i => i.toDouble)
+
+  test("Bounds check") {
+    intercept[vecxt.VectorDimensionMismatch](v_fill.-(Array[Double](1,2,3))(using vecxt.BoundsCheck.yes))
+  }
+
+  test("no bound check") {
+    intercept[java.lang.ArrayIndexOutOfBoundsException](v_fill.-(Array[Double](1,2,3))(using vecxt.BoundsCheck.no))
+  }
+
+end BoundsCheckSuite
diff --git a/tests/shared/src/test/scala/dynamic.scala b/tests/shared/src/test/scala/dynamic.scala
deleted file mode 100644
index 897da4b..0000000
--- a/tests/shared/src/test/scala/dynamic.scala
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
- * Copyright 2023 quafadas
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import ai.dragonfly.math.vector.Vec
-import ai.dragonfly.math.vector.Vec.*
-import narr.NArray
-import vecxt.idx.Index
-import vecxt.idx.*
-import vecxt.vector.dynamic.*
-
-class DynamicTests extends munit.FunSuite:
-
-  // test("Different vector lengths throw errors") {
-  //   val vec2 = Vec.zeros[2]
-  //   val vec3 = Vec.zeros[3]
-
-  //   interceptMessage[ai.dragonfly.math.UnsupportedVectorDimension]("Expected Vector dimension: 3, but observed: 2"){
-  //     vec2 + vec3
-  //   }
-  // }
-
-  test("same length vectors can be added") {
-    val vec2 = Vec.zeros[2]
-    val vec3 = Vec.zeros[3]
-    val idx = Index.none[3]
-    idx.changeAt(0, true)
-    idx.changeAt(1, true)
-    val anotherVec2 = vec3.index(idx)
-    val sum = vec2 +! anotherVec2
-
-    assert(
-      // notice the difference in the operator on the last line vs above
-      compileErrors("""
-    val vec2 = Vec.zeros[2]
-    val vec3 = Vec.zeros[3]
-    val idx = Index.none[3]
-    idx.changeAt(0, true)
-    idx.changeAt(1, true)
-    val anotherVec2 = vec3.index(idx)
-    val sum = vec2 + anotherVec2
-    """).contains("Required: ai.dragonfly.math.vector.Vec[(2 : Int)]")
-    )
-
-    assertEquals(sum.dimension, 2)
-    // assertEquals(sum.sum, 0.0)
-
-  }
-
-end DynamicTests
diff --git a/tests/shared/src/test/scala/index.scala b/tests/shared/src/test/scala/index.scala
deleted file mode 100644
index 226aabb..0000000
--- a/tests/shared/src/test/scala/index.scala
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * Copyright 2023 quafadas
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-//import ai.dragonfly.math.vector.logical.*
-
-import narr.NArray
-import vecxt.idx.Index
-import vecxt.idx.*
-import vecxt.vector.dynamic.*
-import vecxt.vector.logical.*
-//import ai.dragonfly.math.vector.
-
-class IndexTests extends munit.FunSuite:
-
-  lazy val v_fill = ai.dragonfly.math.vector.Vec.tabulate[5](i => i.toDouble)
-
-  // println(v_fill.render())
-
-  test(" ways of making index ") {
-    val v_idx: Index[5] = Index.none[5]
-
-    val noResults = v_fill.index(v_idx)
-    assertEquals(noResults.dimension, 0)
-
-    v_idx.changeAt(1, true)
-    v_idx.changeAt(2, true)
-
-    assertEquals(v_idx.countTrue, 2)
-
-    val indexed = v_fill.index(v_idx)
-    assertEquals(indexed.dimension, 2)
-    assertEquals(indexed(0), 1.0)
-    assertEquals(indexed(1), 2.0)
-  }
-
-  test("<=") {
-    val v_idx2: Index[5] = v_fill < 2.5
-    assertEquals(v_idx2.countTrue, 3)
-  }
-
-  test("<") {
-    val v_idx2: Index[5] = v_fill < 3.0
-    assertEquals(v_idx2.countTrue, 3)
-  }
-
-  test(">") {
-    val v_idx2: Index[5] = v_fill > 2.5
-    assertEquals(v_idx2.countTrue, 2)
-  }
-
-  test(">=") {
-    val v_idx2: Index[5] = v_fill >= 3.0
-    assertEquals(v_idx2.countTrue, 2)
-  }
-
-  test("&&") {
-    val v_idx2: Index[5] = (v_fill < 3.0) && (v_fill > 1.0)
-    assertEquals(v_idx2.countTrue, 1)
-  }
-
-  test("||") {
-    val v_idx2: Index[5] = (v_fill < 3.0) || (v_fill > 1.0)
-    assertEquals(v_idx2.countTrue, 5)
-
-    val v_idx3: Index[5] = (v_fill < 1.0) || (v_fill > 4.0)
-    assertEquals(v_idx3.countTrue, 1)
-  }
-
-end IndexTests
diff --git a/tests/shared/src/test/scala/rpt.test.scala b/tests/shared/src/test/scala/rpt.test.scala
index 8b281cc..b1d3cda 100644
--- a/tests/shared/src/test/scala/rpt.test.scala
+++ b/tests/shared/src/test/scala/rpt.test.scala
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package vexct
+package vecxt
 
 import Retentions.*
 import Limits.*