(En) Language Common Sense

In English

theory
The difference between ‘theory’ and ‘theorem’.
A theory is a rational type of abstract thinking about a phenomenon, or the results of such thinking. —Wikipedia
In mathematics, a theorem is a statement that has been proved, or can be proved.[a][2][3] —Wikipedia
Taste: Information theory and asymptotic equipartition theorem.

i.e. source
abbreviation for “id est”, a Latin phrase for “that is”, used especially in writing before a piece of information that makes the meaning of something clearer or shows its true meaning.
- The hotel is closed during low season, i.e. from October to March.
- The price must be more realistic, i.e. lower.
e.g. source
abbreviation for “exempli gratia”: a Latin phrase that means “for example”.
- You should eat more food that contains a lot of fibre, e.g. fruit, vegetables, and bread.

QED source
abbreviation for the Latin phrase “quod erat demonstrandum”: written or said after an argument to show that you have proved something that you wanted to prove.
ad hoc source, source
a Latin phrase meaning literally ‘for this’: made or happening only for a particular purpose or need, not planned before it happens:
- on an ad hoc basis We deal with problems on an ad hoc basis (= as they happen).
- an ad hoc committee/meeting

in vivo source
a Latin for “within the living”. It refers to work that’s performed in a whole, living organism.
in vitro source
a Latin for “within the glass”. When something is performed in vitro, it happens outside of a living organism.
in situ source
a Latin phrase that translates literally to “on site” or “in position.

Eigen source
Ansatz source
an educated guess or an additional assumption made to help solve a problem, and which may later be verified to be part of the solution by its results.
Example: see No.4 method to solve linear ODEs.
Statistik source
description of a state, a country.