thanks for your reply.

The following should be the programming function for Lagrangian Interpolation polynomial, which I found somewhere.

?→A: ?→B: ?→C: ?→D: ?→X: ?→Y:

**;** D - B -. 1 DT : (the Y - D) ÷ (X-- C DT ??: D →: → M:

(M - Y) ÷ (D - X→M: (M - Σx ) ÷ (D - C→B:

(D - A) ^{-1} (B - (X - A) ^{-1} ( Σx - n ÷ (C - A→A◢

B - A(D +X + C→B◢ D + X: M - BAns - A(DAns + X ^{2 }→C ◢

Y - AX ^{3} - BX ^{2} - AnsX → D

You can see the semicolon in the second row. It may be a mistake by the author, but I wonder what should be the corresponding correct symbol?