I could not find the page /80a066ccbfe7c688fe33f2b018a549620b6c731e/understandingFunctions/digInForEachInputExactlyOneOutput but I will look into the cause of this error.
/80a066ccbfe7c688fe33f2b018a549620b6c731e/understandingFunctions/digInForEachInputExactlyOneOutput