Exercise on the uses of assert

[tekkac]

Description

Show that Cairo uses the assert keyword for two purposes:

• Verifying a value against a memory location
• Assigning a value to a memory location

Resource:

• https://www.cairo-lang.org/docs/hello_cairo/intro.html#the-assert-statement
• https://www.cairo-lang.org/docs/how_cairo_works/consts.html#the-assert-statement-and-compound-expressions

Acceptance criteria

• The exercise shows different uses of assert
• The contract compiles and tests pass
• An exercise patch is generated