v142: RETRACTED v130's span census. Its 1033-span pattern required a space after the label, and the space-form is single-line BY CONSTRUCTION - a filter that guaranteed its own answer. All 3381 spans are 53.83% multi-line, mean 1.8953, max 13, with 17 nesting depths. STRUCTURAL EXHAUSTION withdrawn, line-relation family reopens with a 4847-line surface. Backrefs verified 315/315 backward. 1057 tests
