The convex presupposes the concave; and vam is related to vap (as somnus is related to hpnos, to svapnas, and to sopor).
sopor so·por (sō'pər, -pôr')
A deep, lethargic, or unnatural sleep.
: the Sooner football team
A native or resident of Oklahoma (1930+)
[fr the fact that some settlers entered the public land and staked their claims sooner than the legal date and hour in 1889]