u4.64.02 Operator DEFI_BASE_MODALE# 1. But 2. Syntax 3. Operands 3.1. Keyword factor CLASSIQUE 3.2. Keyword factor RITZ 3.3. Keyword factor DIAG_MASS 3.4. Keyword factor ORTHO_BASE 3.5. Keyword factor SOLVEUR 3.6. Operand TITRE 3.7. Operand INFO 4. Examples 4.1. Dynamic substructuring 4.2. Enrichment of a natural mode database with static modes