Thanks for the question

Will someone please explain example C in english

CREATE TABLE T (a int, b int, c int);

GO

INSERT INTO T VALUES (1, 1, -3), (2, 2, 4), (3, 1, NULL), (4, 3, 1), (5, 2, NULL), (6, 1, 5);

SELECT b, c,

LEAD(2*c, b*(SELECT MIN(b) FROM T), -c/2.0) OVER (ORDER BY a) AS i

FROM T;

I am very confused over the first parameter 2*c