Syntax errors like incorrect or missing punctuation while using curves will result in TEX or LATEX error messages. The TEXbook and LATEX manual explain the meaning and correction of these errors. The previous examples and Section
should make the correct syntax for curves commands clear.
curves will write a LaTeX er+ror. message to the screen and log file if you supply an incorrect number of coordinates.
If four sequential points in a drawing command argument have the line through the first and third parallel to the line through the second and fourth:
If four sequential points in a drawing command argument have the line through the first and second parallel to the line through the third and fourth:
||exactly or closely, curves knows it cannot draw a parabola tangent to two parallel lines, issues to the screen and log file:
LaTeX Warning: \curve straight from ...
and draws a straight line;
||or approximately, curves may draw an unexpected curve with no warning.