mapping spectrum

In algebraic topology, the mapping spectrum $F(X,\; Y)$ of spectra X, Y is characterized by

:$[X\; \backslash wedge\; Y,\; Z]\; =\; [X,\; F(Y,\; Z)].${{cite web|url=https://mathoverflow.net/q/200422 |title=homology of a mapping spectrum|work=MathOverflow}}