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							|  |  |  | 	<title>implements_protocol/2-3</title> | 
					
						
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							|  |  |  | <h2><code><a class="back" title="Return to index" href="../index.html#implements_protocol2_3">implements_protocol/2-3</a></code></h2> | 
					
						
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							|  |  |  | <h4>Description</h4> | 
					
						
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							|  |  |  | <blockquote> | 
					
						
							|  |  |  | <pre> | 
					
						
							|  |  |  | implements_protocol(Object, Protocol) | 
					
						
							|  |  |  | implements_protocol(Category, Protocol) | 
					
						
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							|  |  |  | implements_protocol(Object, Protocol, Scope) | 
					
						
							|  |  |  | implements_protocol(Category, Protocol, Scope) | 
					
						
							|  |  |  | </pre> | 
					
						
							|  |  |  | <p> | 
					
						
							|  |  |  | 	Enumerates, by backtracking, all pairs of entities such that an object or a category implements a protocol. | 
					
						
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							|  |  |  | <h4>Template and modes</h4> | 
					
						
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							|  |  |  | <blockquote> | 
					
						
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							|  |  |  | implements_protocol(?object_identifier, ?protocol_identifier) | 
					
						
							|  |  |  | implements_protocol(?category_identifier, ?protocol_identifier) | 
					
						
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										 |  |  | implements_protocol(?object_identifier, ?protocol_identifier, ?scope) | 
					
						
							|  |  |  | implements_protocol(?category_identifier, ?protocol_identifier, ?scope) | 
					
						
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										 |  |  | </pre> | 
					
						
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										 |  |  | <h4>Errors</h4> | 
					
						
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							|  |  |  | 		<dt>Object is neither a variable nor a valid object identifier:</dt> | 
					
						
							|  |  |  | 			<dd><code>type_error(object_identifier, Object)</code></dd> | 
					
						
							|  |  |  | 		<dt>Category is neither a variable nor a valid category identifier:</dt> | 
					
						
							|  |  |  | 			<dd><code>type_error(category_identifier, Category)</code></dd> | 
					
						
							|  |  |  | 		<dt>Protocol is neither a variable nor a valid protocol identifier:</dt> | 
					
						
							|  |  |  | 			<dd><code>type_error(protocol_identifier, Protocol)</code></dd> | 
					
						
							|  |  |  | 		<dt>Scope is neither a variable nor a valid entity scope:</dt> | 
					
						
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										 |  |  | 			<dd><code>type_error(scope, Scope)</code></dd> | 
					
						
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										 |  |  | 	</dl> | 
					
						
							|  |  |  | </blockquote> | 
					
						
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							|  |  |  | <h4>Examples</h4> | 
					
						
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							|  |  |  | <blockquote> | 
					
						
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							|  |  |  | | ?- implements_protocol(List, listp). | 
					
						
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							|  |  |  | | ?- implements_protocol(List, listp, public). | 
					
						
							|  |  |  | </pre> | 
					
						
							|  |  |  | </blockquote> | 
					
						
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							|  |  |  | <strong><a href="extends_protocol2_3.html">Previous</a> | <a href="imports_category2_3.html">Next</a> | <a href="../index.html">Table of Contents</a> | <a href="../../bibliography.html">Bibliography</a> | <a href="../../glossary.html">Glossary</a></strong> | 
					
						
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											2001-12-05 23:57:48 +00:00
										 |  |  | Last updated on: October 21, 2001 | 
					
						
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