Two terms M and N are observationally equivalent iff for all contexts C where C[M] is a valid term, C[N] is also a valid term with the same value.
[ob-zur-vey-shuh-nl] /ˌɒb zɜrˈveɪ ʃə nl/ adjective 1. of, relating to, or founded on , especially founded on rather than experiment.
noun 1. a railroad passenger car having a lounge or platform from which the scenery can be viewed. noun 1. a railway carriage fitted with large expanses of glass to provide a good view of the scenery
- Observation deck
noun a platform or open area on top of a tall building or natural feature from which the public may view the surrounding panorama Examples How many proposals could the observation deck of the Empire State Building have seen in its 75 years? Word Origin 1941
noun, Military. 1. a forward position, often on high ground, from which enemy activity can be observed and, particularly, from which artillery or mortar fire can be directed. noun 1. (military) a position from which observations can be made or from which fire can be directed OP noun a place from which something may be […]