 This refutes the contention of Barzin and Errera. Note that these points are all in Brouwer’s writings, too. Indeed, Heyting (1932: 121) objects to Barzin and Errera’s term “Heyting’s logic”, saying that “all the fundamental ideas of that logic come from Brouwer” (translation mine). But Heyting’s papers will have found a wider audience than Brouwer’s. Brouwer, in turn, was very positive about the paper Heyting 1930C, and wrote to the editor of the journal in which it appeared (Brouwer to de Donder, October 9, 1930):