In topology for two topological spaces X{\displaystyle X} and Y{\displaystyle Y} two continuous maps f,g:X→Y{\displaystyle f,g:X\to Y} are called homotopic if there is a continuous map F:X×[0,1]→Y{\displaystyle F:X\times [0,1]\to Y} such that f(x)=F(x,0){\displaystyle f(x)=F(x,0)} and g(x)=F(x,1){\displaystyle g(x)=F(x,1)} for all x{\displaystyle x} in X{\displaystyle X}.