         let expression = Expression(kind: .function(op.function, [operand]), range: range)
         
         let replacementRange = operandIndex ... operatorIndex
-        collapsedWrappers.replaceSubrange(replacementRange, with: [.Expression(expression)])
+        collapsedWrappers.replaceSubrange(replacementRange, with: [.expression(expression)])
         
         index = operandIndex
         return collapsedWrappers

        }
        
        let replacementExpressionRange = index ... operandIndex
        collapsedWrappers.replaceSubrange(replacementExpressionRange, with: [.Expression(expression)])
        
        return collapsedWrappers
    }

        let expression = Expression(kind: .function(op.function, [leftOperand, rightOperand]), range: range)
        
        let replacementRange = leftIndex ... rightIndex
        collapsedWrappers.replaceSubrange(replacementRange, with: [.expression(expression)])
        
        return collapsedWrappers
    }
