One of the surprising developments in the area of program verification is how several ideas introduced by logicians in the first part of the 20th century ended up yielding at the start of the 21st century industry-standard property-specification languages called PSL and SVA. This development was enabled by the equally unlikely transformation of the mathematical machinery of automata on infinite words, introduced in the early 1960s for second-order arithmetics, into effective algorithms for industrial model-checking tools. This talk attempts to trace the tangled threads of this development.