  The spontaneous symmetry breaking in (1+1)-dimensional $\phi^{4}$ theory is
studied with discretized light-front quantization, that is, by solving the
zero-mode constraint equation. The symmetric ordering is assumed for the
operator-valued constraint equation. The commutation relation between the zero
mode and each oscillator mode is calculated with $\hbar$ expansion. A critical
coupling evaluated from the first some terms in the expansion is $28.8\mu
^{2}/\hbar \le \lambda_{cr} \le 31.1\mu ^{2}/\hbar$ consistent with the
equal-time one $22\mu ^{2}/\hbar \le \lambda_{cr} \le 55.5\mu ^{2}/\hbar$. The
same analysis is also made under another operator ordering.
