机构具有确定运动的条件是()。
A. 自由度大于零
B. 自由度等于零
C. 自由度大于零且与原动件数相等
复合铰链的转动副数等于()。
A. 构件数-1
B. 构件数
C. 可动构件数-1
A grammar G is defined as a 4-tuple (VN,VT,P,S )VNis a set of nonterminalsVTis a set of terminalsP is a set of productions,each production consists of a left side,an arrow(or ‘::=’),and a right sideS is a designation of one of the nonterminalsas the start symbolV =VN ∪ VT is the alphabet of G
A. 对
B. 错
Type 3: context-free grammarsProductions are of the form X→v where v is an arbitrary string of symbols in V, and X is a single nonterminal. Wherever you find X, you can replace with v (regardless of context).
A. 对
B. 错