Question 636868
The argument <font color="red">invalid</font>. Draw out the table to get


<TABLE BORDER=1 CELLPADDING=5>
<TR ALIGN=center>
  <TD>V</TD>
  <TD>W</TD>
  <TD>V->W</TD>
  <TD>W</TD>
  <TD>V</TD>
</TR>
<TR ALIGN=center>
  <TD>T</TD>
  <TD>T</TD>
  <TD>T</TD>
  <TD>T</TD>
  <TD>T</TD>
</TR>
<TR ALIGN=center>
  <TD>T</TD>
  <TD>F</TD>
  <TD>F</TD>
  <TD>F</TD>
  <TD>T</TD>
</TR>
<TR ALIGN=center>
  <TD>F</TD>
  <TD>T</TD>
  <TD>T</TD>
  <TD>T</TD>
  <TD>F</TD>
</TR>
<TR ALIGN=center>
  <TD>F</TD>
  <TD>F</TD>
  <TD>T</TD>
  <TD>F</TD>
  <TD>F</TD>
</TR>
</TABLE>



The premises are columns 3 and 4. The conclusion is column 5.


Notice how row 3 has all true premises, but a false conclusion. So this shows us that this argument is <font color="red">invalid</font>.


<TABLE BORDER=1 CELLPADDING=5>
<TR ALIGN=center>
  <TD>V</TD>
  <TD>W</TD>
  <TD>V->W</TD>
  <TD>W</TD>
  <TD>V</TD>
</TR>
<TR ALIGN=center>
  <TD>T</TD>
  <TD>T</TD>
  <TD>T</TD>
  <TD>T</TD>
  <TD>T</TD>
</TR>
<TR ALIGN=center>
  <TD>T</TD>
  <TD>F</TD>
  <TD>F</TD>
  <TD>F</TD>
  <TD>T</TD>
</TR>
<TR ALIGN=center>
  <TD>F</TD>
  <TD>T</TD>
  <TD><font color="red">T</font></TD>
  <TD><font color="red">T</font></TD>
  <TD><font color="red">F</font></TD>
</TR>
<TR ALIGN=center>
  <TD>F</TD>
  <TD>F</TD>
  <TD>T</TD>
  <TD>F</TD>
  <TD>F</TD>
</TR>
</TABLE>