´)𝔽´ 𝕩: FoldFold over 𝕩 with 𝔽 from right to left i.e. Insert 𝔽 between the elements of 𝕩.
𝕩 must be a simple list (1 = =𝕩).
+´ 1‿2‿3 6 1+2+3 6 -´ 1‿2‿3 2 1-2-3 2
𝕨 𝔽´ 𝕩: Fold With InitialMonadic fold, but use 𝕨 as initial right argument.
5 +´ 1‿2‿3 11 1+2+3+5 11 5 -´ 1‿2‿3 ¯3 1-2-3-5 ¯3