mistake in the rule of the binary operator?

Hi,
I'm student of the master's degree in computer science of the Federal University of Paraná (Brazil), and analyzing the document XQUERY 1.0 FORMAL SEMANTICS in the last version, I found in the item 5.4 the description of the unary operator, as shown below:  
  
 
      E |- Expr1 => v1      a2 = apply(Op, a1)  

--------------------------------------------------------------------------
     
      E |- Op Expr1 => a2  


But, it seems that a small mistake exists in this rule (shown in red). Am I correct in my statement?

  
      E |- Expr1 => a1      a2 = apply(Op, a1)  

--------------------------------------------------------------------------
     
      E |- Op Expr1 => a2  



 

Best Regards.

Edenilson Silva
CEFET/PR - Pato Branco