# Questioned equal to character (≟) not valid in expression

**URL:** <https://forum.universal-robots.com/t/questioned-equal-to-character-not-valid-in-expression/6167>\
**Category:** URCap Development\
**Tags:** java-error\
**Created:** [January 27, 2020, 8:33am UTC](https://forum.universal-robots.com/t/questioned-equal-to-character-not-valid-in-expression/6167 "2020-01-27T08:33:47Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![anon3164729](https://avatars.discourse-cdn.com/v4/letter/a/87869e/32.png) [@anon3164729](https://forum.universal-robots.com/u/anon3164729)\
**Post date:** [January 27, 2020, 8:33am UTC](https://forum.universal-robots.com/t/questioned-equal-to-character-not-valid-in-expression/6167/1 "2020-01-27T08:33:47Z")

</div>

I want to create a child If node with my URCap, with the condition: test≟"test". Is this possible?

I obtained the ≟ Unicode character in this way:

```
Ctrl + Shift + U -> 225f -> Space

```

This is the Java code to create the If node:

```
manager = apiProvider.getProgramAPI().getUndoRedoManager();	
contribution = apiProvider.getProgramAPI().getInstallationNode(PatternSelectorInstallationNodeContribution.class);
programNodeFactory = apiProvider.getProgramAPI().getProgramModel().getProgramNodeFactory();
	
ProgramAPI programAPI = apiProvider.getProgramAPI();
ProgramModel programModel = programAPI.getProgramModel();
rootTreeNode = programModel.getRootTreeNode(this);
lockTreeNodes();
	
IfNode ifNode = programNodeFactory.createIfNode();
	
try {
	ExpressionBuilder builder = apiProvider.getProgramAPI().getValueFactoryProvider().createExpressionBuilder();
	Expression expression;
	try {
		expression = builder.append("test").append("≟").append("\"test\"").build(); 
		ifNode = ifNode.setExpression(expression);
	} catch (InvalidExpressionException e) {
		e.printStackTrace();
	}
	ifTreeNode = rootTreeNode.addChild(ifNode);
} catch (TreeStructureException e1) {
	e1.printStackTrace();
}

```

The condition in the If node is empty, while if I write `<` instead of `≟` I see the correct condition _If test\<“test”_.

This is the first part of the error in the console:

```
com.ur.urcap.api.domain.value.expression.InvalidExpressionException: Lexer exception on line 1: var_1 = test≟"test"
at com.ur.urcap.domain.expression.ExpressionParser.checkValidity(ExpressionParser.java:34)
at com.ur.urcap.domain.expression.ExpressionParser.parseExpression(ExpressionParser.java:23)
at com.ur.urcap.domain.expression.ExpressionBuilderImpl.build_aroundBody20(ExpressionBuilderImpl.java:83)
at com.ur.urcap.domain.expression.ExpressionBuilderImpl$AjcClosure21.run(ExpressionBuilderImpl.java:1)
at org.aspectj.runtime.reflect.JoinPointImpl.proceed(JoinPointImpl.java:149)
at com.ur.polyscope.valueobjects.aspects.UncaughtExceptionAspect.aroundMethod(UncaughtExceptionAspect.java:24)
at com.ur.urcap.domain.expression.ExpressionBuilderImpl.build(ExpressionBuilderImpl.java:82)
```

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<div class="post-metadata">

**Author:** ![fujikit](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.universal-robots.com/fujikit/32/6042_2.png) [@fujikit](https://forum.universal-robots.com/u/fujikit)\
**Post date:** [January 27, 2020, 8:39am UTC](https://forum.universal-robots.com/t/questioned-equal-to-character-not-valid-in-expression/6167/2 "2020-01-27T08:39:32Z")

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I also cannot build the expression “≟” in if-node.  
So I use the expression “==” as an alternative.

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<div class="post-metadata">

**Author:** ![mbush](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.universal-robots.com/mbush/32/76_2.png) [@mbush](https://forum.universal-robots.com/u/mbush)\
**Post date:** [January 29, 2020, 4:07pm UTC](https://forum.universal-robots.com/t/questioned-equal-to-character-not-valid-in-expression/6167/3 "2020-01-29T16:07:09Z")

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In script code ‘==‘ is the logical expression for equivalency.

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<div class="post-metadata">

**Author:** ![system](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.universal-robots.com/system/32/1_2.png) [@system](https://forum.universal-robots.com/u/system)\
**Post date:** [January 19, 2021, 4:11pm UTC](https://forum.universal-robots.com/t/questioned-equal-to-character-not-valid-in-expression/6167/4 "2021-01-19T16:11:33Z")

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