- Palouse to Cascades Trail - The Tunnel (wta.org)
Washington State has a plethora of amazingly beautiful trails for the avid hiker to tread, but how many take you through an old train tunnel more than two miles long? The Snoqualmie Tunnel is part of the 250-mile Palouse to Cascades State Park Trail (formerly the John Wayne Trail and Iron Horse State Park). Views for most of your trip will be determined by the power of your headlamp, but there will be some sights on the other side. The attraction of this hike is the mysterious, dramatic tunnel itself. However, note that the tunnel is closed November 1st through May 1st, so plan your trip accordingly.
- Universal quantification (Wikipedia)
In mathematical logic, a universal quantification is a type of quantifier, a logical constant which is interpreted as “given any”, “for all”, or “for any”. It expresses that a predicate can be satisfied by every member of a domain of discourse. In other words, it is the predication of a property or relation to every member of the domain. It asserts that a predicate within the scope of a universal quantifier is true of every value of a predicate variable.