document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=569541>Question 569541</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Prove that the following argument is not valid. \"If it rains, crops will be good\" if it did not rain, therefore, crops were not good. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #367360 by </B><A HREF=/tutors/aboutme.mpl?userid=richard1234><B>richard1234(7193)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=richard1234><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=richard1234><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=367360\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I haven't taken formal logic, but it is possible that crops will be good even if it doesn't rain. This is like saying \"If a quadrilateral is a square, it is a rectangle.\" However, the obverse \"If a quadrilateral is a rectangle, it is a square\" is not always true. It is true if and only if the relation is one-to-one.\r<BR>\n" );
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document.write( "However, the contrapositive is always true and equivalent to the original statement: \"If crops are not good, it did not rain.\" </SPAN>\n" );
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