I wonder what made the authors of the language make the pattern matching statement keyword `mat`. Like... they were 2 characters away from a perfectly readable

I wonder what made the authors of the language make the pattern matching statement keyword `mat`. Like... they were 2 characters away from a perfectly readable name, yet they've settled up on something that's confusing (took me a while to grasp it). Guess the time and space savings are worth it, though.