Question: What did Ernst Mach foreshadow in his study with assistant Anton Wassmuth? 
Sentence (from "Relativity priority dispute"): Albert Einstein presented the theories of special relativity and general relativity in groundbreaking publications that either contained no formal references to previous literature, or referred only to a small number of his predecessors for fundamental results on which he based his theories, most notably to the work of Hendrik Lorentz for special relativity, and to the work of Carl F. Gauss, Bernhard Riemann, and Ernst Mach for general relativity.
Relevant evidence: No