Alvarus Thomas or Álvaro Tomás (d. 1521) from Lisbon, master at the University of Paris (regens of the College of Coqueret, at least 1509-1513), doctor of medicine in 1518, is a little known historical figure. His Liber de triplici motu is the only work by him known today. It presents a comprehensive and sophisticated analysis of the theory of proportions and of the science of motion, treated in the characteristic way of the tradition of the Oxford Calculators. Besides some interesting criticism of contemporary physical theories, this work is also relevant from the point of view of mathematics since Thomas achieves some good results in his study of infinite series. Some of these aspects have been treated in the specialized literature (see our Bibliography).
Alvarus Thomas finished his book in 1509 (probably 1510 in our counting) with the title “Book on the three [kinds of] movement, with [a treatise on] ratios appended, by Master Alvarus Thomas of Lisbon, explaining in part Swineshead’s philosophical calculations”, by the printer Guillaume Anabat (fl. 1505-1510).
[Title page] Liber de triplici motu proportionibus annexis magistri Alvari Thomae Ulixbonensis philosophicas Suiseth calculationes ex parte declarans,
[Colophone] Explicit liber de triplici motu compositus per Magistrum Aluarum Thomam vlixbonensem Regentem Parrhisius in Collegio Coquereti. Anno domini. 1509. Die Februarii. 11
Impressum Parris[iis]: per Guillermum Anabat … ex[p]ensis Po[n]seti le Preux, 
The book turns out to be not very rare (see our Census), but there are at least three states of the edition, as is evident from different frontispieces and the composition of the first page: