(mathematics) A mathematical problem, asking whether a room with mirrored walls can always be illuminated by a single-point light source, allowing for repeated reflection of light off the mirrored walls. It was solved in 1958: there are such rooms that cannot be thus illuminated.

plural of decision problem

(computing theory) A question in some formal system with a yes-or-no answer, depending on the values of input parameters.

plural of problem play

(theater) A form of drama that emerged in the 19th century as part of realism, dealing with contentious social issues through debates between the characters on stage, who typically represent conflicting points of view within a realistic social context.

plural of halting problem

(mathematics, mathematical analysis) For a given m-order partial differential equation, the problem of finding a solution function u on ℝⁿ that satisfies the boundary conditions that, for a smooth manifold S⊂ℝⁿ, u(x)=f_0(x) and (∂ᵏu(x))/(∂nᵏ)=f_k(x), ∀x∈S, k=1…m-1, given specified functions f_k defined on, and vector n normal to, the manifold.

plural of Cauchy problem

plural of problem bear

A bear that poses a danger to humans because it has adapted to human activities or habitat.