1 files changed, 1 insertions, 1 deletions
diff --git a/u/fn/either.ts b/u/fn/either.ts
index 8b233bf..b228af2 100644
--- a/u/fn/either.ts
+++ b/u/fn/either.ts
@@ -10,7 +10,7 @@ export interface IEither<E, T> {
     errBranch: Mapper<E, Ee>,
     okBranch: Mapper<T, Tt>,
   ) => IEither<Ee, Tt>;
-  fold: <Tt>(folder: BiMapper<E | undefined, T | undefined, Tt>) => Tt;
+  fold: <Tt>(folder: (err: E | undefined, val: T | undefined) => Tt) => Tt; //BiMapper<E | undefined, T | undefined, Tt>) => Tt;;
   moveRight: <Tt>(t: Tt) => IEither<E, Tt>;
   mapRight: <Tt>(mapper: Mapper<T, Tt>) => IEither<E, Tt>;
   mapLeft: <Ee>(mapper: Mapper<E, Ee>) => IEither<Ee, T>;