Original sentence: Thus, a hammer with a bronze head could not infringe the notional claim under the doctrine of equivalents
Edited sentence: In deciding whether a material is substantially different from that literally recited in a patent claim, a court can use statements in the patent itself.Thus, a bronze hammer head might be found to be "equivalent" to the literally-claimed iron head, while a Styrofoam head would likely not be found equivalent; the issue is whether the new material (bronze or Styrofoam) differs "substantially" from the iron material literally recited in the claim