Saxon

Hi, I'm trying to apply a xquery file to a xml file. While parsing the xquery file i already receive warnings like: @Warning on line 38 column 8 of Mapping.xq: Branch 1 of conditional will fail with a type error if executed. Required item type of result of call to vmf:myFunction is xs:boolean; supplied value has item type xs:integer@

When executing i get the error: @Type error on line 38 column 29 of Mapping.xq: XPTY0004: Required item type of result of call to vmf:myFunction is xs:boolean; supplied value has item type xs:integer net.sf.saxon.s9api.SaxonApiException: Required item type of result of call to vmf:myFunction is xs:boolean; supplied value has item type xs:integer at net.sf.saxon.s9api.XQueryEvaluator.run(XQueryEvaluator.java:372) at my.project.Transformer.xqueryFunction(Transformer.java:166) at my.project.Transformer.importFiles(Transformer.java:873) at my.project.Main.main(Main.java:40) Caused by: net.sf.saxon.trans.XPathException: Required item type of result of call to vmf:myFunction is xs:boolean; supplied value has item type xs:integer at net.sf.saxon.expr.ErrorExpression.evaluateItem(ErrorExpression.java:125) at net.sf.saxon.expr.ErrorExpression.iterate(ErrorExpression.java:148) at net.sf.saxon.expr.instruct.Choose.iterate(Choose.java:909) at net.sf.saxon.value.Closure.iterate(Closure.java:189) at net.sf.saxon.value.Closure.head(Closure.java:160) at net.sf.saxon.expr.UserFunctionCall.evaluateItem(UserFunctionCall.java:453) at net.sf.saxon.expr.CastExpression.evaluateItem(CastExpression.java:393) at net.sf.saxon.expr.CastExpression.evaluateItem(CastExpression.java:33) at net.sf.saxon.expr.Expression.process(Expression.java:880) at net.sf.saxon.expr.instruct.ElementCreator.processLeavingTail(ElementCreator.java:364) at net.sf.saxon.expr.instruct.ElementCreator.processLeavingTail(ElementCreator.java:311) at net.sf.saxon.expr.instruct.Instruction.process(Instruction.java:149) at net.sf.saxon.expr.ForExpression.process(ForExpression.java:493) at net.sf.saxon.expr.instruct.Block.processLeavingTail(Block.java:655) at net.sf.saxon.expr.instruct.Instruction.process(Instruction.java:149) at net.sf.saxon.expr.instruct.ElementCreator.processLeavingTail(ElementCreator.java:364) at net.sf.saxon.expr.instruct.ElementCreator.processLeavingTail(ElementCreator.java:311) at net.sf.saxon.expr.instruct.Block.processLeavingTail(Block.java:653) at net.sf.saxon.expr.instruct.Instruction.process(Instruction.java:149) at net.sf.saxon.expr.instruct.ElementCreator.processLeavingTail(ElementCreator.java:364) at net.sf.saxon.expr.instruct.ElementCreator.processLeavingTail(ElementCreator.java:311) at net.sf.saxon.expr.instruct.Instruction.process(Instruction.java:149) at net.sf.saxon.expr.LetExpression.process(LetExpression.java:568) at net.sf.saxon.expr.ForExpression.process(ForExpression.java:493) at net.sf.saxon.expr.ForExpression.process(ForExpression.java:493) at net.sf.saxon.expr.LetExpression.processLeavingTail(LetExpression.java:713) at net.sf.saxon.expr.instruct.Block.processLeavingTail(Block.java:653) at net.sf.saxon.expr.instruct.Instruction.process(Instruction.java:149) at net.sf.saxon.expr.instruct.ElementCreator.processLeavingTail(ElementCreator.java:364) at net.sf.saxon.expr.instruct.ElementCreator.processLeavingTail(ElementCreator.java:311) at net.sf.saxon.expr.instruct.Instruction.process(Instruction.java:149) at net.sf.saxon.query.XQueryExpression.run(XQueryExpression.java:408) at net.sf.saxon.s9api.XQueryEvaluator.run(XQueryEvaluator.java:370) ... 3 more@

The function looks like this: @declare function vmf:myFunction ( $input as xs:string ) as xs:boolean? { if ( $input = 'JA' ) then 1 else if ( $input = 'NEIN' ) then 0 else 0 } ;@

Replacing the 1 and the 0 with true() and false() fixes the error. The problem is that i cannot alter the xquery file. It's a generated file from Altova Mapforce. Can i somehow tell Saxon to interpret the integer value like a boolean? Thanks in advance Scree