1) Section 4.9, last sentence of first paragraph:

REPLACE: "the index expressions is not" with “the index expression is not”.

2) Section 4.9, third paragraph:

REPLACE: “associative an associative” with “an associative”

3) Section 4.10.2, paragraph 2 and 3:

REPLACE: "delete method" with"delete() method" with delete() in bold

4) 4) Section 4.10.4, last paragraph:

"The first() function" should be "The first() method"