Combining two cells into one...

[rbbydotdev]

  const allMd$ = Cell("", (realm) => {
    realm.sub(markdown$, (md) => {
      realm.pub(allMd$, md);
    });
    realm.sub(markdownSourceEditorValue$, (md) => {
      realm.pub(allMd$, md);
    });
  }),

Is this the only way two combine two cells into one? I see combine but but it gives you an array, I want a singular raced to value. Does such a thing exist? I cannot for the life of me find it