Detailed Analysis:

• Claim: Thieves snatch eight Matisse artworks from library in Brazil.
• Verification Source #1: Confirms the theft of eight Matisse artworks from a library in Brazil.
• Verification Source #2: Confirms the theft of eight Matisse artworks from a library in Brazil.
• Verification Source #3: Confirms the theft of eight Matisse artworks from a library in Brazil.
• Verification Source #4: Confirms the theft of 8 Matisse works from a library in Brazil.
• Verification Source #5: Confirms the theft of eight Matisse artworks from a library in Brazil.
• Assessment: Supported
• Claim: The thieves enter the library in normal opening hours, stuffing the art works into a canvas bag.
• Verification Source #2: States that the thieves entered during normal opening hours and stuffed the artworks into a canvas bag.
• Assessment: Unverified, but not contradicted. Other sources do not provide this level of detail.
• Claim: Two armed men have stolen eight engravings by French artist Matisse and at least another five by Brazilian painter Cândido Portinari
• Verification Source #1: States that two armed men stole eight engravings by Matisse and at least five by Cândido Portinari.
• Verification Source #4: States that two armed men stole over a dozen pieces of art.
• Assessment: Partially Contradicted. Source 1 and 4 mention two armed men, while the original article does not specify the number of thieves. Source 1 specifies the theft of works by both Matisse and Portinari, while the original article focuses solely on Matisse. Source 4 mentions over a dozen pieces of art were stolen, which contradicts the original article's focus on eight Matisse artworks.