Given the exceptional circumstances under which this work has been undertaken, the evidence set out in this document is presented at a high level, focusing on the most substantial changes.
O gofio'r amgylchiadau eithriadol a fu'n sail i ymgymryd â'r gwaith hwn, cyflwynir y dystiolaeth a nodir yn y ddogfen hon ar lefel uchel, gan ganolbwyntio ar y newidiadau mwyaf sylweddol.