diff --git a/src/object_chain.ts b/src/object_chain.ts
index 098db73..3c1b9ad 100644
--- a/src/object_chain.ts
+++ b/src/object_chain.ts
@@ -6,14 +6,14 @@ import * as ctag from "./chain_tag.ts"
 import {
     CastUCObjectStepSpec,
     UCFxObjectStepSpec, UCPureObjectStepSpec,
-    ObjectChainSteps, UPObjectStepSpec,
+    ObjectChainSteps, UPObjectStepSpec, ObjectStepSpecList,
     ObjectStepsTupleReqsU,
     ObjectStepsErrorsU, ObjectChainStepsReturn, objectChainStepsProg
 } from "./object_chain_steps.ts"
 
 // an effectful function of Input which build an Object
 export type ObjectChainProgram<Input extends ChainTagged,
-    Steps extends cons.NRConsList<UPObjectStepSpec>> =
+    Steps extends ObjectStepSpecList> =
     (i: Input) => Effect.Effect<
         ObjectStepsTupleReqsU<Steps>,
         ObjectStepsErrorsU<Steps>,
@@ -22,18 +22,18 @@ export type ObjectChainProgram<Input extends ChainTagged,
 
 // a type for a service which can run an ObjectChain
 export type ObjectChainService<Input extends ChainTagged,
-    Steps extends cons.NRConsList<UPObjectStepSpec>> = {
+    Steps extends ObjectStepSpecList> = {
         readonly buildObject: ObjectChainProgram<Input, Steps>
     }
 
 export type ObjectChainServiceContextTag<Input extends ChainTagged,
-    Steps extends cons.NRConsList<UPObjectStepSpec>> =
+    Steps extends ObjectStepSpecList> =
     Context.Tag<ChainTag<Input>, ObjectChainService<Input, Steps>>
 
 // get a Context.Tag for an ObjectChainService
 export function objectChainServiceContextTag
     <Input extends ChainTagged,
-        Steps extends cons.NRConsList<UPObjectStepSpec>>
+        Steps extends ObjectStepSpecList>
     () {
     return Context.Tag<ChainTag<Input>, ObjectChainService<Input, Steps>>()
 }
@@ -42,7 +42,7 @@ export function objectChainServiceContextTag
 // Object. it can be built in a single step with objectChain, or iteratively 
 // with addSteps
 export type ObjectChain<Input extends ChainTagged,
-    Steps extends cons.NRConsList<UPObjectStepSpec>,
+    Steps extends ObjectStepSpecList,
     // this param is only here so that a chain value's IntelliSense 
     // shows the chain's return type
     _Return = ObjectChainStepsReturn<Steps, Input>> = {
@@ -63,7 +63,7 @@ export type UPObjectChain = {
     // deno-lint-ignore no-explicit-any
     readonly tag: any
     readonly tagStr: string
-    readonly steps: cons.NRConsList<UPObjectStepSpec>
+    readonly steps: ObjectStepSpecList
     // deno-lint-ignore no-explicit-any
     readonly program: (i: any) => Effect.Effect<any, any, any>
     // deno-lint-ignore no-explicit-any
@@ -102,7 +102,7 @@ export type UPObjectChainProgramValue<T extends UPObjectChain> =
 
 // build an ObjectChain from Steps
 export function objectChain<Input extends ChainTagged>() {
-    return function <const Steps extends cons.NRConsList<UPObjectStepSpec>>
+    return function <const Steps extends ObjectStepSpecList>
         (tag: ChainTag<Input>,
 
             steps: Steps extends ObjectChainSteps<Steps, Input>
@@ -126,7 +126,7 @@ export function objectChain<Input extends ChainTagged>() {
 // add a FxStep to an ObjectChain, returning a new ObjectChain
 export function addStep
     <Input extends ChainTagged,
-        const Steps extends cons.NRConsList<UPObjectStepSpec>,
+        const Steps extends ObjectStepSpecList,
         NewStep extends UPObjectStepSpec>
 
     (chain: ObjectChain<Input, Steps>,
@@ -146,7 +146,7 @@ export function addStep
 // make an FxStep at the end of an ObjectChain, returning a new ObjectChain
 export function makeFxStep
     <Input extends ChainTagged,
-        const Steps extends cons.NRConsList<UPObjectStepSpec>,
+        const Steps extends ObjectStepSpecList,
         K extends string,
         A extends ObjectChainStepsReturn<Steps, Input>,
         D1 extends D2,
@@ -168,7 +168,7 @@ export function makeFxStep
 // make a PureStep at the end of an ObjectChain, returning a new ObjectChain
 export function makePureStep
     <Input extends ChainTagged,
-        const Steps extends cons.NRConsList<UPObjectStepSpec>,
+        const Steps extends ObjectStepSpecList,
         K extends string,
         A extends ObjectChainStepsReturn<Steps, Input>,
         V>(chain: ObjectChain<Input, Steps>,
@@ -185,8 +185,8 @@ export function makePureStep
 // return a new ObjectChain with the addSteps concatenated
 export function concatSteps
     <Input extends ChainTagged,
-        const ChainSteps extends cons.NRConsList<UPObjectStepSpec>,
-        const AddSteps extends cons.NRConsList<UPObjectStepSpec>>
+        const ChainSteps extends ObjectStepSpecList,
+        const AddSteps extends ObjectStepSpecList>
     (chain: ObjectChain<Input, ChainSteps>,
         addSteps: AddSteps extends cons.ConsList<UPObjectStepSpec, AddSteps>
             ? AddSteps
@@ -214,7 +214,7 @@ export function concatSteps
 export function objectChainServiceImpl
 
     <Input extends ChainTagged,
-        const Steps extends cons.NRConsList<UPObjectStepSpec>>
+        const Steps extends ObjectStepSpecList>
 
     (chain: ObjectChain<Input, Steps>) {
 
@@ -231,7 +231,7 @@ export function objectChainServiceImpl
 // to an Effect
 export function provideObjectChainServiceImpl
     <Input extends ChainTagged,
-        const Steps extends cons.NRConsList<UPObjectStepSpec>,
+        const Steps extends ObjectStepSpecList,
         InR, InE, InV>
 
     (effect: Effect.Effect<InR, InE, InV>,
@@ -248,7 +248,7 @@ export function provideObjectChainServiceImpl
 // calls it's buildObject function
 export function objectChainFxFn
     <Input extends ChainTagged,
-        const Steps extends cons.NRConsList<UPObjectStepSpec>>
+        const Steps extends ObjectStepSpecList>
 
     (chain: ObjectChain<Input, Steps>) {
 
diff --git a/src/object_chain_steps.ts b/src/object_chain_steps.ts
index 3fd9280..ccf9f1d 100644
--- a/src/object_chain_steps.ts
+++ b/src/object_chain_steps.ts
@@ -146,6 +146,8 @@ export function objectStepFn<Obj>() {
     }
 }
 
+export type ObjectStepSpecList = NRConsList<UPObjectStepSpec>
+
 // utility type to get a Union from a Tuple of types
 // deno-lint-ignore no-explicit-any
 export type UnionFromTuple<Tuple extends readonly any[]> = Tuple[number]
@@ -163,7 +165,7 @@ export type ExpandTuple<Tuple extends readonly [...any[]]> = {
 } & { length: Tuple['length'] }
 
 // convert a cons list of UPObjectStepSpecs type to a Tuple type
-export type ObjectStepsTuple<Steps extends NRConsList<UPObjectStepSpec>> =
+export type ObjectStepsTuple<Steps extends ObjectStepSpecList> =
     ToTuple<UPObjectStepSpec, Steps>
 
 // get a union of all the Requirements from a list of steps...
@@ -174,12 +176,12 @@ export type ObjectStepReqs<T extends UPObjectStepSpec> =
     ? R
     : never
 export type ObjectStepsReqsU<
-    List extends NRConsList<UPObjectStepSpec>,
+    List extends ObjectStepSpecList,
     Acc = never> = 
     List extends None
     ? Acc
     : List extends readonly [infer F extends UPObjectStepSpec,
-        infer R extends NRConsList<UPObjectStepSpec>]
+        infer R extends ObjectStepSpecList]
     ? ObjectStepsReqsU<R, Acc | ObjectStepReqs<F>>
     : never
 type ObjectStepsTupleReqsUImpl<
@@ -192,7 +194,7 @@ type ObjectStepsTupleReqsUImpl<
 // setting up the recursion Service in object_chain.ts ...converting 
 // the list to a tuple before extracting the Requirements union seems 
 // to avoid that
-export type ObjectStepsTupleReqsU<Steps extends NRConsList<UPObjectStepSpec>> =
+export type ObjectStepsTupleReqsU<Steps extends ObjectStepSpecList> =
     ObjectStepsTupleReqsUImpl<ObjectStepsTuple<Steps>>
 
 // get a union of all the Errors from a list of steps
@@ -202,12 +204,12 @@ export type ObjectStepErrors<T extends UPObjectStepSpec> =
     ? E
     : never
 export type ObjectStepsErrorsU<
-    List extends NRConsList<UPObjectStepSpec>,
+    List extends ObjectStepSpecList,
     Acc = never> =
     List extends None
     ? Acc
     : List extends readonly [infer F extends UPObjectStepSpec,
-        infer R extends NRConsList<UPObjectStepSpec>]
+        infer R extends ObjectStepSpecList]
     ? ObjectStepsErrorsU<R, Acc | ObjectStepErrors<F>>
     : never
 
@@ -218,13 +220,13 @@ export type ObjectStepInput<T extends UPObjectStepSpec> =
     ? A
     : never
 export type ObjectStepsInputTuple<
-    List extends NRConsList<UPObjectStepSpec>,
+    List extends ObjectStepSpecList,
     // deno-lint-ignore no-explicit-any
     Acc extends readonly any[] = []> =
     List extends None
     ? Acc
     : List extends readonly [infer F extends UPObjectStepSpec,
-        infer R extends NRConsList<UPObjectStepSpec>]
+        infer R extends ObjectStepSpecList]
     ? ObjectStepsInputTuple<R, readonly [...Acc, ObjectStepInput<F>]>
     : never
 
@@ -235,13 +237,13 @@ export type ObjectStepValue<T extends UPObjectStepSpec> =
     ? V
     : never
 export type ObjectStepsValueTuple<
-    List extends NRConsList<UPObjectStepSpec>,
+    List extends ObjectStepSpecList,
     // deno-lint-ignore no-explicit-any
     Acc extends readonly any[] = []> =
     List extends None
     ? Acc
     : List extends readonly [infer F extends UPObjectStepSpec,
-        infer R extends NRConsList<UPObjectStepSpec>]
+        infer R extends ObjectStepSpecList]
     ? ObjectStepsValueTuple<R, readonly [...Acc, ObjectStepValue<F>]>
     : never
 
@@ -261,7 +263,7 @@ export type ObjectStepsValueTuple<
 // 2. it's safe to use never in the else branches. they will not be hit
 
 export type ObjectChainSteps<
-    Specs extends NRConsList<UPObjectStepSpec>,
+    Specs extends ObjectStepSpecList,
     ObjAcc> =
 
     // case: no more specs
@@ -270,7 +272,7 @@ export type ObjectChainSteps<
 
     // case: there are more specs - add a property to ObjAcc and recurse
     : Specs extends readonly [infer First,
-        infer Rest extends NRConsList<UPObjectStepSpec>]
+        infer Rest extends ObjectStepSpecList]
     ? First extends UCFxObjectStepSpec<
         infer FK, infer _FA, infer _FD1, infer FD2,
         infer FR, infer FE, infer FV>
@@ -285,7 +287,7 @@ export type ObjectChainSteps<
 
 // get the final Object result type from a list of ObjectStepSpecs
 export type ObjectChainStepsReturn<
-    Specs extends NRConsList<UPObjectStepSpec>,
+    Specs extends ObjectStepSpecList,
     ObjAcc> =
     Specs extends None
     ? ObjAcc // empty specs returns the input
@@ -304,7 +306,7 @@ export type ObjectChainStepsReturn<
 // other type params
 export function objectChainStepsProg<Obj>() {
 
-    return function <const Specs extends NRConsList<UPObjectStepSpec>>
+    return function <const Specs extends ObjectStepSpecList>
         (objectStepSpecs:
             Specs extends ObjectChainSteps<Specs, Obj>
             ? Specs