Jan Willem Klop
Corrado was present since the beginning of my acquaintance with the mother of all calculi, the lambda calculus. In 1975 Henk Barendregt introduced me to this miraculous lambda calculus world, in our research seminar preparing for and prior to Henk's famous book. New terminology was developed, and Henk coined the Dutch phrase Böhm Boom, elsewhere forever known as Böhm Tree. In 1978 in the lambda calculus Ecole de Printemps in La Chatre, France, I took a picture of Corrado and Henk standing and conversing about lambda calculus, under a giant sequoia, a veritable Böhm Boom. Just as we met Corrado numerous times, Böhm Trees (BT's) stayed with us throughout life and work. They turned out to be the paradigm that generated the two other canonical tree semantics of lambda calculus, next to the LLT's and BeT's. Corrado was also an inspiration through his enthousiasm, his gentleness, his curiosity. His life and his work will remain with us as shining examples. Böhm Trees will be here forever.