My goal is to quote two paragraphs using the
amsart document style, with both paragraphs in the quotation being formatted in ordinary paragraph style, i.e. with the crown line indented.
The LaTeX Book on p. 26 says that the "quotation" environment is for quoting material that is entire paragraphs, and shows an example with the formatting I desire. The AMS-LaTeX guide does not describe quotations at all.
Testing shows that in
amsart the "quotation" environment does not indent the first line of the quotation, but if the quotation contains an empty line the first line following it will be indented.
That is, the first paragraph is not paragraph-formatted but the second paragraph is paragraph-formatted. (The "quote" environment produces the same formatting, contra the LaTeX Book which says that "quote" is for non-paragraph-formatted text.)
Presumably there is a known way to do this but I haven't been able to find the documentation.