Work has been done on proving that the sofa constant (A) cannot be below or above certain values (lower bounds and upper bounds).

Lower
An obvious lower bound is A \geq \pi/2 \approx 1.57. This comes from a sofa that is a half-disk of unit radius, which can rotate in the corner.

John Hammersley derived a lower bound of A \geq \pi/2 + 2/\pi \approx 2.2074 based on a shape resembling a telephone handset, consisting of two quarter-disks of radius 1 on either side of a 1 by 4/\pi rectangle from which a half-disk of radius. 

In 1992, Joseph L. Gerver of Rutgers University described a sofa described by 18 curve sections each taking a smooth analytic form. This further increased the lower bound for the sofa constant to approximately 2.2195.

Upper

Hammersley also found an upper bound on the sofa constant, showing that it is at most 2\sqrt{2} \approx 2.8284. 

Yoav Kallus and Dan Romik proved a new upper bound in June 2017, capping the sofa constant at 2.37.
Extract the most recent upper bound and low bound of the sofa constant and return them in the format {Bound Type} - {Bound Value}.
The soft constant has the following bounds: Upper Bound - 2.37, Lower Bound - 2.2195.