onto
preposition
- moving to the top of
Wiktionary
Pronunciation: /ˈɒn.tuː/ / /ˈɑn.tu/ / /ˈɔn.tu/
adj
Etymology: From on + to, after into. Compare Saterland Frisian antou (“up to”).
- Attaining each of the values in its codomain; having its image equal to its codomain.
“Considered as a function on the real numbers, the exponential function is not onto, as it never takes on values less than or equal to zero.”
prep
Etymology: From on + to, after into. Compare Saterland Frisian antou (“up to”).
- Arriving upon or on top of (speaking of a physical or metaphorical movement).
“My cat just jumped onto the keyboard.”
“A new drug has just come onto the market.”
- Aware of.
“The thought-police were onto my plans of world domination.”
- Being an onto function with a codomain of (see below).
“The exponential function maps the set of real numbers onto the set of positive real numbers.”