.#if 1
True.
.#;
.#if -f xhtml
xhtml.
.#;
.#if -f xhtml 0
False and xhtml.
.#;
.#if -f xhtml 1
True and xhtml.
.#;
.\" nested if
.#if 1
True
.#if 0
False
.#;
True;
.#;
.\" No close
.#if 1
.#if 1
True
