<PRE><B>Question 4140</B>
&gt;&gt;what is the meaning of conditional statement.

A statement of the form &quot;If P is true, then Q is true&quot;, often
written &quot; P =&gt; Q&quot;

&gt;&gt;...what [are] the two parts of it...&lt;&lt;&lt;

The antecedent (P) and the consequence (Q).

&gt;&gt;...and also can you please define &quot;converse&quot; and &quot;inverse&quot;. please also define the following: 1. contrapositive...&lt;&lt;

These are three conditionals which are related to P =&gt; Q; but only the contrapositive is equivalent to it:

Converse of P=&gt;Q is Q=&gt;P
Inverse of P=&gt;Q is ~P=&gt;~Q
Contrapositive of P=&gt;Q is ~Q=&gt;~P


&lt;&lt;&gt;&gt;2. tautology&lt;&lt;&gt;&gt;

A logical statement which is true regardless of the truth or falsity 
of the variables.

&lt;&lt;&gt;&gt;3. contradiction&lt;&lt;&gt;&gt;

A logical statement which is false regardless of the truth or falsity 
of the variables.

Example:  ~(P /\ Q) &lt;=&gt; ~P \/ ~Q


 4. logical equivalence

P and Q are logically equivalent if P=&gt;Q and Q=&gt;P.

Edwin</PRE>