D. J. A. Welsh
= D. J. A. Welsh
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D. J. A. Welsh coauthored a study of square-lattice <bond percolation> with <P. D. Seymour>. Their crossing-probability arguments relate crossings of squares to crossings of rectangles. These estimates help control connectivity across different scales and form part of <Russo-Seymour-Welsh theorem>.<Percolation probabilities on the square lattice by P. D. Seymour and D. J. A. Welsh>[Introduction and Sections 4–5]{ref}