assume() in texmacs



Hello everybody, i just installed latest version of texmacs to work with maxima(version of Maxima is 5.23.2)  But i texmacs does not work function assume()
I typed:
assume(a-b<0)
Texmacs replies:
"incorrect syntax: Found logical expression where algebraic expression
expected"
In terminal (xterm) all works fine.
What is wrong?