The end of the 4th sentence of the 2nd paragraph reads:

"... and sends the result back to the requester using the message send
requester ! sum."

It should read:

"... and sends the result back to the requester using the message send
requester ! c

Section 1.4, Paragraph 3, Sentence 2:
"Scala programs often look a bit like programs written in a dynamically
typeddynamic!typing scripting language."
I guess should be:
"Scala programs often look a bit like programs written in a dynamically
typed scripting language."

[FIXED]