Church's thesis (constructive mathematics)
In constructive mathematics, Church's thesis C T {\displaystyle {\mathrm {CT} }} is the principle stating that all total functions are computable functions. The similarly named Church–Turing thesis states that every effectively calculable function is a computable function, thus collapsing the former notion into the latter.
Source: Wikipedia — Church's thesis (constructive mathematics) (CC BY-SA 4.0)