| <html><head><META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>5.2.3. Base Logical Term</title><link href="style.css" rel="stylesheet" type="text/css"><meta content="DocBook XSL Stylesheets V1.72.0" name="generator"><link rel="start" href="index.html" title="The VIATRA2 Model Transformation Framework"><link rel="up" href="sec_ASMLogicalTerms.html" title="5.2. Logical Terms"><link rel="prev" href="def_ConjLogicalTerm.html" title="5.2.2. Conjunctive Logical Term (Logical And Term)"><link rel="next" href="sec_ASMArithmeticTerms.html" title="5.3. Arithmetic Terms"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table summary="Navigation header" width="100%"><tr><th align="center" colspan="3">5.2.3. Base Logical Term</th></tr><tr><td align="left" width="20%"><a accesskey="p" href="def_ConjLogicalTerm.html">Prev</a> </td><th align="center" width="60%">5.2. Logical Terms</th><td align="right" width="20%"> <a accesskey="n" href="sec_ASMArithmeticTerms.html">Next</a></td></tr></table><hr></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="def_BaseLogicalTerm"></a>5.2.3. Base Logical Term</h4></div></div></div><div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Tip: Description"><tr><td valign="top" align="center" rowspan="2" width="25"><img alt="[Tip]" src="images/tip.png"></td><th align="left"><a name="def_BaseLogicalTerm_Description"></a>Description</th></tr><tr><td valign="top" align="left"><p> | |
| A <span class="strong"><strong>base logical term</strong></span><a name="N1216D" class="indexterm"></a> | |
| is the most elementary ASM term that evaluates to a boolean value. | |
| </p></td></tr></table></div><div class="important" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Important: Syntax"><tr><td valign="top" align="center" rowspan="2" width="25"><img alt="[Important]" src="images/important.png"></td><th align="left"><a name="def_BaseLogicalTerm_Syntax"></a>Syntax</th></tr><tr><td valign="top" align="left"><pre class="programlisting"> | |
| EqualityTermAST ::= RelationalTermAST | |
| | EqualityTermAST <span class="token">==</span> RelationalTermAST | |
| | EqualityTermAST <span class="token">!=</span> RelationalTermAST | |
| RelationalTermAST ::= <a href="def_ArithmeticTerm.html" title="5.3.1. Arithmetic Term">ArithmeticTermAST</a> | |
| | RelationalTermAST RelationalOpAST <a href="def_ArithmeticTerm.html" title="5.3.1. Arithmetic Term">ArithmeticTermAST</a> | |
| RelationalOpAST ::= <span class="token"><</span> | <span class="token">></span> | <span class="token"><=</span> | <span class="token">>=</span> | |
| </pre><p> | |
| A <span class="strong"><strong>base logical term</strong></span><a name="N1219A" class="indexterm"></a> can be the following: | |
| </p><div class="itemizedlist"><ul type="disc"><li><p>a relational expression</p></li><li><p>an <a href="def_ArithmeticTerm.html" title="5.3.1. Arithmetic Term">arithmetic term</a>, which evaluates to a boolean value, such as | |
| <div class="itemizedlist"><ul type="circle"><li><p>a <a href="def_BooleanConstant.html" title="5.4.3. Boolean Constant">boolean constant</a>, | |
| </p></li><li><p>the negation of a <span class="strong"><strong>base logical term</strong></span>, | |
| </p></li><li><p>a general <a href="def_LogicalTerm.html" title="5.2.1. Logical Term">logical term</a> surrounded with parenthesis, | |
| </p></li><li><p>a <a href="def_GraphPatternCall.html" title="2.1.4. Graph Pattern Call">graph pattern call</a>. | |
| </p></li></ul></div> | |
| </p></li></ul></div><p> | |
| A <span class="emphasis"><em>relational expression</em></span>is a relation between two | |
| <a href="def_ArithmeticTerm.html" title="5.3.1. Arithmetic Term">arithmetic terms</a>; the relational operator can be equality operators | |
| (like equal, <code class="computeroutput">$==$</code> and not equal, <code class="computeroutput">!=</code>) or inequality operators such as | |
| <code class="computeroutput">></code>, <code class="computeroutput"><</code>, <code class="computeroutput">>=</code>, | |
| <code class="computeroutput"><=</code> (where the latter has higher precedence). | |
| </p></td></tr></table></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Note: Semantics"><tr><td valign="top" align="center" rowspan="2" width="25"><img alt="[Note]" src="images/note.png"></td><th align="left"><a name="def_BaseLogicalTerm_Semantics"></a>Semantics</th></tr><tr><td valign="top" align="left"><p> | |
| A <a href="def_GraphPatternCall.html" title="2.1.4. Graph Pattern Call">graph pattern call</a> results <code class="computeroutput">true</code> if a matching is found | |
| and <code class="computeroutput">false</code> otherwise. | |
| </p><p> | |
| Relational operators are interpreted between data types according to | |
| <a href="def_BaseLogicalTerm.html#tab_EqualNotEqual" title="Table 2.4. Equal (==) and Not Equal (!=) operators">Table 2.4, “Equal (<code class="computeroutput">==</code>) and Not Equal (<code class="computeroutput">!=</code>) operators ”</a> and <a href="def_BaseLogicalTerm.html#tab_Inequality" title="Table 2.5. Other relational inequality operators (<, >, <=, >=) and Not Equal (!=) operators">Table 2.5, “Other relational inequality operators (<code class="computeroutput"><, >, <=, >=</code>) and Not Equal (<code class="computeroutput">!=</code>) operators ”</a>. | |
| The cells in the tables define the type of the result when evaluating a relational | |
| expression with arguments of a specific datatype. | |
| </p><p> | |
| <span class="emphasis"><em>Equality</em></span> (and <span class="emphasis"><em>!=</em></span>) can be tested for any kinds of operands, | |
| but the other relations are limited. Semantically the <span class="emphasis"><em>less than</em></span> and | |
| <span class="emphasis"><em>greater than</em></span> relations are the usual (Java) ones for the <code class="computeroutput">Integer</code> | |
| and <code class="computeroutput">Double</code> values. Regarding <code class="computeroutput">Multiplicity</code> values, | |
| <div class="itemizedlist"><ul type="disc"><li><p> | |
| <code class="computeroutput">one-to-one</code> is less than <code class="computeroutput">many-to-many</code>, | |
| <code class="computeroutput">many-to-one</code>, and <code class="computeroutput">one-to-many</code>, | |
| </p></li><li><p> | |
| <code class="computeroutput">one-to-many</code> and <code class="computeroutput">many-to-one</code> is less than | |
| <code class="computeroutput">many-to-many</code>; | |
| </p></li><li><p> | |
| but <code class="computeroutput">one-to-many</code> and <code class="computeroutput">many-to-one</code> are uncomparable to each other. | |
| </p></li></ul></div> | |
| </p><div class="table"><a name="tab_EqualNotEqual"></a><p class="title"><b>Table 2.4. Equal (<code class="computeroutput">==</code>) and Not Equal (<code class="computeroutput">!=</code>) operators </b></p><div class="table-contents"><table summary="Equal (==) and Not Equal (!=) operators " border="1"><colgroup><col><col><col><col><col><col><col><col></colgroup><thead><tr><th align="center"> </th><th align="center">Undef</th><th align="center">Boolean</th><th align="center">String</th><th align="center">Integer</th><th align="center">Double</th><th align="center">ModelElement</th><th align="center">Multiplicity</th></tr></thead><tbody><tr><td align="center"><span class="strong"><strong>Undef</strong></span></td><td align="center">Undef</td><td align="center">Undef</td><td align="center">Undef</td><td align="center">Undef</td><td align="center">Undef</td><td align="center">Undef</td><td align="center">Undef</td></tr><tr><td align="center"><span class="strong"><strong>Boolean</strong></span></td><td align="center">Undef</td><td align="center">Bool</td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td></tr><tr><td align="center"><span class="strong"><strong>String</strong></span></td><td align="center">Undef</td><td align="center"> </td><td align="center">Bool</td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td></tr><tr><td align="center"><span class="strong"><strong>Integer</strong></span></td><td align="center">Undef</td><td align="center"> </td><td align="center"> </td><td align="center">Bool</td><td align="center">Bool</td><td align="center"> </td><td align="center"> </td></tr><tr><td align="center"><span class="strong"><strong>Double</strong></span></td><td align="center">Undef</td><td align="center"> </td><td align="center"> </td><td align="center">Bool</td><td align="center">Bool</td><td align="center"> </td><td align="center"> </td></tr><tr><td align="center"><span class="strong"><strong>ModelElement</strong></span></td><td align="center">Undef</td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center">Bool</td><td align="center"> </td></tr><tr><td align="center"><span class="strong"><strong>Multiplicity</strong></span></td><td align="center">Undef</td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center">Bool</td></tr></tbody></table></div><p></p></div><br class="table-break"><div class="table"><a name="tab_Inequality"></a><p class="title"><b>Table 2.5. Other relational inequality operators (<code class="computeroutput"><, >, <=, >=</code>) and Not Equal (<code class="computeroutput">!=</code>) operators </b></p><div class="table-contents"><table summary="Other relational inequality operators (<, >, <=, >=) and Not Equal (!=) operators " border="1"><colgroup><col><col><col><col><col><col><col><col></colgroup><thead><tr><th align="center"> </th><th align="center">Undef</th><th align="center">Boolean</th><th align="center">String</th><th align="center">Integer</th><th align="center">Double</th><th align="center">ModelElement</th><th align="center">Multiplicity</th></tr></thead><tbody><tr><td align="center"><span class="strong"><strong>Undef</strong></span></td><td align="center">Undef</td><td align="center">Undef</td><td align="center">Undef</td><td align="center">Undef</td><td align="center">Undef</td><td align="center">Undef</td><td align="center">Undef</td></tr><tr><td align="center"><span class="strong"><strong>Boolean</strong></span></td><td align="center">Undef</td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td></tr><tr><td align="center"><span class="strong"><strong>String</strong></span></td><td align="center">Undef</td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td></tr><tr><td align="center"><span class="strong"><strong>Integer</strong></span></td><td align="center">Undef</td><td align="center"> </td><td align="center"> </td><td align="center">Bool</td><td align="center">Bool</td><td align="center"> </td><td align="center"> </td></tr><tr><td align="center"><span class="strong"><strong>Double</strong></span></td><td align="center">Undef</td><td align="center"> </td><td align="center"> </td><td align="center">Bool</td><td align="center">Bool</td><td align="center"> </td><td align="center"> </td></tr><tr><td align="center"><span class="strong"><strong>ModelElement</strong></span></td><td align="center">Undef</td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td></tr><tr><td align="center"><span class="strong"><strong>Multiplicity</strong></span></td><td align="center">Undef</td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center"> </td><td align="center">Bool</td></tr></tbody></table></div><p></p></div><br class="table-break"></td></tr></table></div><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Warning: Warning"><tr><td valign="top" align="center" rowspan="2" width="25"><img alt="[Warning]" src="images/warning.png"></td><th align="left"><a name="def_BaseLogicalTerm_Warning"></a>Warning</th></tr><tr><td valign="top" align="left"><p> | |
| Note that the evaluation rules of relational operators changed in the | |
| new release to be compliant with its use in Java. | |
| </p></td></tr></table></div><div class="highlights"><a name="def_BaseLogicalTerm_Remark"></a><p><b>Remark. </b> | |
| There is no implicit type casting on the input of the operands except between Integers and Doubles; conversion | |
| operators have to be used if casting is required. | |
| </p></div><div class="highlights"><a name="def_BaseLogicalTerm_DefinedIn"></a><p><b>Defined In: </b> | |
| <a href="def_ConjLogicalTerm.html" title="5.2.2. Conjunctive Logical Term (Logical And Term)">conjuntive logical term</a> | |
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