The majority of cold-stunned turtles transported by Turtles Fly Too are large adult sea turtles.

Use the Traditional Square of Opposition If an an I-statement is true then the corresponding O-statement is:

“Only proteins are prions” is a Stylistic Variant of:

Use the Traditional Square of Opposition Assuming that “All liars are mendacious ones” is true, what does it imply about the truth or falsity of “No liars are mendacious ones”?

Immediate inference: Identify the relationship using the Traditional Square of Opposition. Then indicate whether the inference is valid: It is true that No astronauts are herbivores. It follows that All astronauts are herbivores is false.

“All circles are shapes” is a necessary truth.

Immediate inference: Identify the relationship using the Traditional Square of Opposition. Then indicate whether the inference is valid:  There are no philosopher kings, so it is false that there are some philosopher kings.

Immediate inference: Identify the relationship using the Traditional Square of Opposition. Then indicate whether the inference is valid: It is true that Some astronauts are herbivores. It follows that Some astronauts are not herbivores.

Immediate inference: Identify the relationship using the Traditional Square of Opposition. Then indicate whether the inference is valid: All vampires are avid connoisseurs of garlic bread. So, it follows that some vampires are avid connoisseurs of garlic bread.

According to the Traditional Square of Opposition an I statement and its subcontrary can both be true.