By default, text is centered at the geometric center of the object it is associated with. The modifier ljust causes the left end to be at the specified point (which means that the text lies to the right of the specified place!), the modifier rjust puts the right end at the place. The modifiers above and below center the text one half line space in the given direction.
Text, <positityle="margin-top: 1em">At the beginning of each picture, ‘figname’ is reset to the vbox name ‘graph’; this command has only a meaning in TeX mode. While the grammar rules allow digits and the underscore in the value of ‘figname’, TeX normally accepts uppercase and lowercase letters only as box names (you have to use ‘\csname’ if you really need to circumvent this limitation).
<any-expr> ::= <expr> <text-expr> <any-expr> <logical-op> <any-expr> ! <any-expr> <logical-op> ::= == | != | && | ’||’ <text-expr> ::= TEXT == TEXT TEXT != TEXT
Logical operators are handled specially by pic since they can deal with text strings also. pic uses strcmp(3) to test for equality of strings; an empty string is considered as ‘false’ for ‘&&’ and ‘||’.
<primitive> ::= box # closed object — rectangle circle # closed object — circle ellipse # closed object — ellipse arc