syms t s
A=[0 1;-1 -1]
expm(A*t)
t=0.1;
expm(A*t)-(eye(2)+A*t+(A*t)^2/factorial(2)+(A*t)^3/factorial(3)+(A*t)^4/factorial(4)+(A*t)^5/factorial(5))
syms t
simplify(inv(expm(A*t))-expm(-A*t))
diff(expm(A*t))-A*expm(A*t)
expm(A*t)-ilaplace(inv(s*eye(2)-A),s,t)