<｜begin▁of▁sentence｜>### Instruction:
As a geologist, imagine you are studying the layers of rock in a particular region. You are exploring four locations: A, B, C, and D. Through your research, you have identified connections between certain locations. Specifically, you have observed a direct path from location A to B, from B to C, and from C to D.

Now, if you need to know whether there is a direct connection between locations A and C, you can think of it in the context of your geological observations. In this scenario, it's like determining if there is a direct geological link between two specific locations within the rock layers you are studying.

To address this, you could use a tool called igraph, which allows you to investigate the connections between these locations, similar to how you would analyze geological features. With igraph, you can use the 'are_connected' function to determine if there is a direct connection between locations A and C in your rock layer network. This could mirror how you might assess the geological connectivity of different stratigraphic units in your research.
### Response:
from igraph import Graph

# Create an igraph graph
vertices = ['A', 'B', 'C', 'D']
edges = [(0, 1), (1, 2), (2, 3)]
g = Graph(edges, directed=False)
g.vs['name'] = vertices

# Check if two vertices are connected
c = g.are_connected('A', 'C')
print(f'Vertices A and C are connected: {c}')
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