Cryptarithm

In the following addition,
COG
COG
YACHT
—–+
SHIPS

Replace every letter with a digit to get a correct addition.
The same letter always represents the same digit and no digit is represented by 2 or more letters.

New puzzles are published at least once a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars. You can check your solution here.

Bongard – Letters

In 1967 the Russian scientist M.M. Bongard published a book containing 100 problems. Each problem consists of 12 small boxes: six boxes on the left and six on the right. Each of the six boxes on the left conforms to a certain rule. Each box on the right contradicts this rule. Your task, of course, is to figure out the rule.

A Bongard problem consists of two groups of 6 images. Each and every of the six images on the left complies wit a certain rule. Each of the 6 images on the right does NOT comply with this rule. What is the rule?

Letters^***/*****

New puzzles are published at least once a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars. You can check your solution here.

I am indebted to Monday Math for the idea for this rule. See video https://www.youtube.com/watch?v=w5oprHOE0NU.