# Error Messages/40674

## Error message examples

 When the fourth parameter, «I», to Function StepInterp is not specified, the array parameters
to StepInterp must have exactly one index in common. However, in this call, there is more than
one index shared by the array parameters, so that implied index is ambiguous. It is recommended that
you declare the index parameter, «I», explicitly, which will avoid this ambiguity.


## Cause

You are calling a function that expects two arrays that have a common index. You have called the function by passing two arrays with more than one index in common. If the arrays being passed have more than one index in common you need to specify the common index you want the function to operate over.

## Remedies

Specify the common index of the passed arrays that you want the function to operate over.